Add config.bcm for accton_as7816_64x to support port breakout.

[chiourung]

Add four config.bcm for row1, row2, row3 and row4.

Signed-off-by: chiourung_huang chiourung_huang@edge-core.com

- What I did
Modify the config.bcm for breakout.

- How I did it
Reserve the port mapping for breakout.

- How to verify it
Load the config.bcm to the DUT, and check the status

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

[lguohan]

what is row{1,2,3,4}? is this for dynamic port breakout?

[chiourung]

There is a limitation for port number. Not all ports can be breakout. So user can choose which row can be breakout. There are 64 ports for as7816_64x, and 16 ports for one row. For now, the new config.bcm can be modified for breakout easily. For future, when the broadcom SAI ready, the new config.bcm don't need any modified for breakout.

[lguohan]

we do not want multiple config.bcm for a single hardware sku.

[CharlieChenEC]

we do not want multiple config.bcm for a single hardware sku.

I think it is flexible enough to change the pointer in the file "sai.profile" to decide which config.bcm shall be used. Could you tell me what is the reason that "multiple config.bcm" is not acceptable?

[CharlieChenEC]

we do not want multiple config.bcm for a single hardware sku.

I think it is flexible enough to change the pointer in the file "sai.profile" to decide which config.bcm shall be used. Could you tell me what is the reason that "multiple config.bcm" is not acceptable?

@lguohan Could you please provide your concern of using multiple config.bcm? What is your suggestion to deal with the complex port breakout restriction without using this proposed method?