ab8500_btemp: Demote initcall sequence

Power supply subsystem creates thermal zone device for the property
'POWER_SUPPLY_PROP_TEMP' which requires thermal subsystem to be ready
before 'ab8500 battery temperature monitor' driver is initialized. ab8500
btemp driver is initialized with subsys_initcall whereas thermal subsystem
is initialized with fs_initcall which causes
thermal_zone_device_register(...) to crash since the required structure
'thermal_class' is not initialized yet:

Unable to handle kernel NULL pointer dereference at virtual address 000000a4
pgd = c0004000
[000000a4] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0    Tainted: G        W     (3.8.0-rc4-00001-g632fda8-dirty #1)
PC is at _raw_spin_lock+0x18/0x54
LR is at get_device_parent+0x50/0x1b8
pc : [<c02f1dd0>]    lr : [<c01cb248>]    psr: 60000013
sp : ef04bdc8  ip : 00000000  fp : c0446180
r10: ef216e38  r9 : c03af5d0  r8 : ef275c18
r7 : 00000000  r6 : c0476c14  r5 : ef275c18  r4 : ef095840
r3 : ef04a000  r2 : 00000001  r1 : 00000000  r0 : 000000a4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5787d  Table: 0000404a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xef04a238)
Stack: (0xef04bdc8 to 0xef04c000)
[...]
[<c02f1dd0>] (_raw_spin_lock+0x18/0x54) from [<c01cb248>] (get_device_parent+0x50/0x1b8)
[<c01cb248>] (get_device_parent+0x50/0x1b8) from [<c01cb8d8>] (device_add+0xa4/0x574)
[<c01cb8d8>] (device_add+0xa4/0x574) from [<c020b91c>] (thermal_zone_device_register+0x118/0x938)
[<c020b91c>] (thermal_zone_device_register+0x118/0x938) from [<c0202030>] (power_supply_register+0x170/0x1f8)
[<c0202030>] (power_supply_register+0x170/0x1f8) from [<c02055ec>] (ab8500_btemp_probe+0x208/0x47c)
[<c02055ec>] (ab8500_btemp_probe+0x208/0x47c) from [<c01cf0dc>] (platform_drv_probe+0x14/0x18)
[<c01cf0dc>] (platform_drv_probe+0x14/0x18) from [<c01cde70>] (driver_probe_device+0x74/0x20c)
[<c01cde70>] (driver_probe_device+0x74/0x20c) from [<c01ce094>] (__driver_attach+0x8c/0x90)
[<c01ce094>] (__driver_attach+0x8c/0x90) from [<c01cc640>] (bus_for_each_dev+0x4c/0x80)
[<c01cc640>] (bus_for_each_dev+0x4c/0x80) from [<c01cd6b4>] (bus_add_driver+0x16c/0x23c)
[<c01cd6b4>] (bus_add_driver+0x16c/0x23c) from [<c01ce54c>] (driver_register+0x78/0x14c)
[<c01ce54c>] (driver_register+0x78/0x14c) from [<c00086ac>] (do_one_initcall+0xfc/0x164)
[<c00086ac>] (do_one_initcall+0xfc/0x164) from [<c02e89c8>] (kernel_init+0x120/0x2b8)
[<c02e89c8>] (kernel_init+0x120/0x2b8) from [<c000e358>] (ret_from_fork+0x14/0x3c)
Code: e3c3303f e5932004 e2822001 e5832004 (e1903f9f)
---[ end trace ed9df72941b5bada ]---

Signed-off-by: Rajanikanth H.V <rajanikanth.hv@stericsson.com>
Cc: stable@vger.kernel.org
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

drivers/power/ab8500_btemp.c

@@ -1126,7 +1126,7 @@ static void __exit ab8500_btemp_exit(void)
 	platform_driver_unregister(&ab8500_btemp_driver);
 }
 
-subsys_initcall_sync(ab8500_btemp_init);
+device_initcall(ab8500_btemp_init);
 module_exit(ab8500_btemp_exit);
 
 MODULE_LICENSE("GPL v2");