i2c: axxia: Fix NULL pointer dereference by ISR

Fix bug where the interrupt handler would dereference a NULL pointer if an
interrupt was received without an ongoing transfer. This error could be
triggered by another party messing with the I2C controller registers.

Unable to handle kernel NULL pointer dereference at virtual address 00000002
pgd = c0403000
[00000002] *pgd=80000000404003, *pmd=00000000
Internal error: Oops: 205 [#1] PREEMPT SMP ARM
Modules linked in: ncp(O)
CPU: 13 PID: 749 Comm: irq/53-20100860 Tainted: G O 3.10.17-rt11-lsi-preempt-rt_8.8.1.14 #1
task: ee928000 ti: ee490000 task.ti: ee490000
PC is at axxia_i2c_isr+0xe0/0x1b4
LR is at irq_forced_thread_fn+0x20/0x64
pc : [<c07a4c2c>]    lr : [<c0489550>]    psr: 40000013
sp : ee491f00  ip : 00000000  fp : c0489530
r10: c0489530  r9 : ee475fc0  r8 : c0a60f80
r7 : 00000001  r6 : c0a72f40  r5 : 00000000  r4 : eeb72e10
r3 : 00000000  r2 : 00000001  r1 : eeb72e10  r0 : 00000035
Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 30c5387d  Table: 2e180500  DAC: 55555555
Process irq/53-20100860 (pid: 749, stack limit = 0xee490240)
Stack: (0xee491f00 to 0xee492000)
1f00: ee475fc0 c0a60f80 00000000 c0489550 ee475fe0 ee490000 00000000 c048984c
1f20: 00000001 c0a72ff8 ee475fc0 00000000 c0489530 ee490020 00000000 c0489640
1f40: c04896fc ef04dd78 00000000 ee475fc0 c04896fc 00000000 00000000 00000000
1f60: 00000000 c044fe68 eebc6fc0 00000000 ee491f9c ee475fc0 00000000 00000000
1f80: ee491f80 ee491f80 00000000 00000000 ee491f90 ee491f90 ee491fac ef04dd78
1fa0: c044fdc4 00000000 00000000 c041af98 00000000 00000000 00000000 00000000
1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[<c07a4c2c>] (axxia_i2c_isr+0xe0/0x1b4) from [<c0489550>] (irq_forced_thread_fn+0x20/0x64)
[<c0489550>] (irq_forced_thread_fn+0x20/0x64) from [<c048984c>] (irq_thread+0x150/0x1b0)
[<c048984c>] (irq_thread+0x150/0x1b0) from [<c044fe68>] (kthread+0xa4/0xa8)
[<c044fe68>] (kthread+0xa4/0xa8) from [<c041af98>] (ret_from_fork+0x14/0x3c)
Code: e5832048 e2840f66 ebf2ce98 e59431a8 (e1d320b2)
---[ end trace 0000000000000002 ]---

Signed-off-by: Anders Berg <anders.berg@lsi.com>
ARM: dts: axxia: Add missing I2C-0 device

Add device node for I2C-0 controller that connects the system FPGA. The device
node is needed to enable user-space access to this device.

Signed-off-by: Anders Berg <anders.berg@lsi.com>
ARM: dts: axxia: Fix typo in compatible string

The compatible string for the ADT7467 device contained a typo which would
result in the device not being activated.

Signed-off-by: Anders Berg <anders.berg@lsi.com>
Merge branch 'aberg-i2c-with-rte' into standard/lsi/base
Merge branch 'standard/lsi/base' into standard/preempt-rt/lsi/base