drm/amdkfd Avoid destroy hqd when GPU is on reset

This reverts commit 5161bba4311f in order to split it into two
different patches, and this will make it easier to understand.

[PATCH 1/2]
porting to gfx10 from
commit 1b0bfcff ("drm/amdgpu: Avoid destroy hqd when GPU is on reset")

Originally, MEC is touched
without GPU initialized first.

Signed-off-by: Jack Zhang <Jack.Zhang1@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>