drm/amdkfd: New IOCTL to allocate queue GWS (v2)

drm/amdkfd: New IOCTL to allocate queue GWS (v2)

Add a new kfd ioctl to allocate queue GWS. Queue
GWS is released on queue destroy.

v2: re-introduce this API with the following fixes squashed in:
- drm/amdkfd: fix null pointer dereference on dev
- drm/amdkfd: Return proper error code for gws alloc API
- drm/amdkfd: Remove GPU ID in GWS queue creation

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>