mfd: mt6360: Fix register driver NULL pointer by adding driver name

mfd: mt6360: Fix register driver NULL pointer by adding driver name

The driver name was accidentally removed when .probe() by was replaced
by .probe_new() during an early patch review.

[  121.243012] EAX: c2a8bc64 EBX: 00000000 ECX: 00000000 EDX: 00000000
[  121.243012] ESI: c2a8bc79 EDI: 00000000 EBP: e54bdea8 ESP: e54bdea0
[  121.243012] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010286
[  121.243012] CR0: 80050033 CR2: 00000000 CR3: 02ec3000 CR4: 000006b0
[  121.243012] Call Trace:
[  121.243012]  kset_find_obj+0x3d/0xc0
[  121.243012]  driver_find+0x16/0x40
[  121.243012]  driver_register+0x49/0x100
[  121.243012]  ? i2c_for_each_dev+0x39/0x50
[  121.243012]  ? __process_new_adapter+0x20/0x20
[  121.243012]  ? cht_wc_driver_init+0x11/0x11
[  121.243012]  i2c_register_driver+0x30/0x80
[  121.243012]  ? intel_lpss_pci_driver_init+0x16/0x16
[  121.243012]  mt6360_pmu_driver_init+0xf/0x11
[  121.243012]  do_one_initcall+0x33/0x1a0
[  121.243012]  ? parse_args+0x1eb/0x3d0
[  121.243012]  ? __might_sleep+0x31/0x90
[  121.243012]  ? kernel_init_freeable+0x10a/0x17f
[  121.243012]  kernel_init_freeable+0x12c/0x17f
[  121.243012]  ? rest_init+0x110/0x110
[  121.243012]  kernel_init+0xb/0x100
[  121.243012]  ? schedule_tail_wrapper+0x9/0xc
[  121.243012]  ret_from_fork+0x19/0x24
[  121.243012] Modules linked in:
[  121.243012] CR2: 0000000000000000
[  121.243012] random: get_random_bytes called from init_oops_id+0x3a/0x40 with crng_init=0
[  121.243012] ---[ end trace 38a803400f1a2bee ]---
[  121.243012] EIP: strcmp+0x11/0x30

Fixes: 7edd363421dab ("mfd: Add support for PMIC MT6360")
Signed-off-by: Gene Chen <gene_chen@richtek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@kernel.org>
[Lee: Taking the opportunity to fix the compatible string too 's/_/-/']
Signed-off-by: Lee Jones <lee.jones@linaro.org>