[platform] Add support for Arista DCS-7260CX3-64 (#863)

* Update sonic-platform-modules-arista submodule

* Update boot0 to handle DCS-7260CX3-64

* Add sys eeprom plugin for DCS-7260CX3-64

* Add sfputil plugin for DCS-7260CX3-64

* Add sensors config for DCS-7260CX3-64

* Add Arista-7260CX3-64 HwSku port_config

* Handle slow flash partition re-read

* Add minigraph.xml for DCS-7260CX3-64 64x100G

device/arista/x86_64-arista_7260cx3_64/Arista-7260CX3-64/port_config.ini

@@ -0,0 +1,67 @@
+# name          lanes             alias        port
+Ethernet0       77,78,79,80       Ethernet1/1  1
+Ethernet4       65,66,67,68       Ethernet2/1  2
+Ethernet8       85,86,87,88       Ethernet3/1  3
+Ethernet12      89,90,91,92       Ethernet4/1  4
+Ethernet16      109,110,111,112   Ethernet5/1  5
+Ethernet20      97,98,99,100      Ethernet6/1  6
+Ethernet24      117,118,119,120   Ethernet7/1  7
+Ethernet28      5,6,7,8           Ethernet8/1  8
+Ethernet32      17,18,19,20       Ethernet9/1  9
+Ethernet36      13,14,15,16       Ethernet10/1 10
+Ethernet40      29,30,31,32       Ethernet11/1 11
+Ethernet44      37,38,39,40       Ethernet12/1 12
+Ethernet48      49,50,51,52       Ethernet13/1 13
+Ethernet52      45,46,47,48       Ethernet14/1 14
+Ethernet56      61,62,63,64       Ethernet15/1 15
+Ethernet60      121,122,123,124   Ethernet16/1 16
+Ethernet64      193,194,195,196   Ethernet17/1 17
+Ethernet68      133,134,135,136   Ethernet18/1 18
+Ethernet72      205,206,207,208   Ethernet19/1 19
+Ethernet76      213,214,215,216   Ethernet20/1 20
+Ethernet80      225,226,227,228   Ethernet21/1 21
+Ethernet84      221,222,223,224   Ethernet22/1 22
+Ethernet88      237,238,239,240   Ethernet23/1 23
+Ethernet92      245,246,247,248   Ethernet24/1 24
+Ethernet96      141,142,143,144   Ethernet25/1 25
+Ethernet100     249,250,251,252   Ethernet26/1 26
+Ethernet104     149,150,151,152   Ethernet27/1 27
+Ethernet108     153,154,155,156   Ethernet28/1 28
+Ethernet112     173,174,175,176   Ethernet29/1 29
+Ethernet116     161,162,163,164   Ethernet30/1 30
+Ethernet120     181,182,183,184   Ethernet31/1 31
+Ethernet124     185,186,187,188   Ethernet32/1 32
+Ethernet128     69,70,71,72       Ethernet33/1 33
+Ethernet132     73,74,75,76       Ethernet34/1 34
+Ethernet136     93,94,95,96       Ethernet35/1 35
+Ethernet140     81,82,83,84       Ethernet36/1 36
+Ethernet144     101,102,103,104   Ethernet37/1 37
+Ethernet148     105,106,107,108   Ethernet38/1 38
+Ethernet152     1,2,3,4           Ethernet39/1 39
+Ethernet156     113,114,115,116   Ethernet40/1 40
+Ethernet160     9,10,11,12        Ethernet41/1 41
+Ethernet164     21,22,23,24       Ethernet42/1 42
+Ethernet168     33,34,35,36       Ethernet43/1 43
+Ethernet172     25,26,27,28       Ethernet44/1 44
+Ethernet176     41,42,43,44       Ethernet45/1 45
+Ethernet180     53,54,55,56       Ethernet46/1 46
+Ethernet184     125,126,127,128   Ethernet47/1 47
+Ethernet188     57,58,59,60       Ethernet48/1 48
+Ethernet192     129,130,131,132   Ethernet49/1 49
+Ethernet196     197,198,199,200   Ethernet50/1 50
+Ethernet200     209,210,211,212   Ethernet51/1 51
+Ethernet204     201,202,203,204   Ethernet52/1 52
+Ethernet208     217,218,219,220   Ethernet53/1 53
+Ethernet212     229,230,231,232   Ethernet54/1 54
+Ethernet216     241,242,243,244   Ethernet55/1 55
+Ethernet220     233,234,235,236   Ethernet56/1 56
+Ethernet224     253,254,255,256   Ethernet57/1 57
+Ethernet228     137,138,139,140   Ethernet58/1 58
+Ethernet232     157,158,159,160   Ethernet59/1 59
+Ethernet236     145,146,147,148   Ethernet60/1 60
+Ethernet240     165,166,167,168   Ethernet61/1 61
+Ethernet244     169,170,171,172   Ethernet62/1 62
+Ethernet248     189,190,191,192   Ethernet63/1 63
+Ethernet252     177,178,179,180   Ethernet64/1 64
+Ethernet256     257               Ethernet65   65
+Ethernet260     259               Ethernet66   66

device/arista/x86_64-arista_7260cx3_64/Arista-7260CX3-64/sai.profile

@@ -0,0 +1 @@
+SAI_INIT_CONFIG_FILE=/etc/bcm/th2-a7260cx3-64-64x100G.config.bcm