drm/amdgpu: wrong array index to get ip block for PSP

The adev->ip_blocks array is not indexed by AMD_IP_BLOCK_TYPE_xxx,
instead we should call amdgpu_device_ip_get_ip_block() to get the
corresponding IP block oject.

Fix some checkpatch issues (Alex)

Signed-off-by: Jiang Liu <gerry@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>