drm/amd: Fix NULL pointer dereference in device cleanup

In the Linux kernel, the following vulnerability has been resolved:

drm/amd: Fix NULL pointer dereference in device cleanup

When GPU initialization fails due to an unsupported HW block

IP blocks may have a NULL version pointer. During cleanup in

amdgpu_device_fini_hw, the code calls amdgpu_device_set_pg_state and

amdgpu_device_set_cg_state which iterate over all IP blocks and access

adev->ip_blocks[i].version without NULL checks, leading to a kernel

NULL pointer dereference.

Add NULL checks for adev->ip_blocks[i].version in both

amdgpu_device_set_cg_state and amdgpu_device_set_pg_state to prevent

dereferencing NULL pointers during GPU teardown when initialization has

failed.

(cherry picked from commit b7ac77468cda92eecae560b05f62f997a12fe2f2)