drm/amdgpu: Fix kernel panic during driver load failure

drm/amdgpu: Fix kernel panic during driver load failure

Avoid kernel panic if MES init fails during driver load. The KIQ ring is
falsely marked as ready as ASICs that use MES, KIQ is owned by MES.

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:gfx_v12_1_wait_reg_mem+0x5a/0x1f0 [amdgpu]
Call Trace:
 gfx_v12_1_ring_emit_reg_write_reg_wait+0x1f/0x30 [amdgpu]
 amdgpu_gmc_fw_reg_write_reg_wait+0xb2/0x190 [amdgpu]
 amdgpu_gmc_flush_gpu_tlb+0x1cc/0x230 [amdgpu]
 amdgpu_gart_invalidate_tlb+0x81/0xa0 [amdgpu]
 amdgpu_gart_unbind+0x72/0x90 [amdgpu]
 amdgpu_ttm_backend_unbind+0xa4/0xb0 [amdgpu]
 amdgpu_ttm_tt_unpopulate+0x13/0xd0 [amdgpu]
 amdttm_tt_unpopulate+0x29/0x70 [amdttm]
 ttm_bo_put+0x1eb/0x360 [amdttm]
 amdgpu_bo_free_kernel+0xf9/0x1f0 [amdgpu]
 amdgpu_ih_ring_fini+0x5a/0x90 [amdgpu]
 amdgpu_irq_fini_hw+0x58/0x80 [amdgpu]
 amdgpu_device_fini_hw+0x4e0/0x5b0 [amdgpu]
 amdgpu_driver_load_kms+0x60/0xa0 [amdgpu]
 amdgpu_pci_probe+0x28e/0x6d0 [amdgpu]
 pci_device_probe+0x19f/0x220
 really_probe+0x1ed/0x340
 driver_probe_device+0x1e/0x80
 __driver_attach+0xd3/0x1a0
 bus_for_each_dev+0x68/0xa0
 bus_add_driver+0x19f/0x270
 driver_register+0x5d/0xf0
 do_one_initcall+0xac/0x200
 do_init_module+0x1ec/0x280
 __se_sys_finit_module+0x2de/0x310
 do_syscall_64+0x6a/0x250
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>