drm/amdgpu: add new AMDGPU_INFO subquery for userq objects

drm/amdgpu: add new AMDGPU_INFO subquery for userq objects

This patch adds a new subquery (AMDGPU_INFO_UQ_FW_AREAS) in
AMDGPU_INFO_IOCTL to get the size and alignment of shadow
and csa objects from the FW setup. This information is
required for the userqueue consumers.

V2: Added Alex's suggestions and addressed review comments:
- make this query IP specific (GFX/SDMA etc)
- give a better title (AMDGPU_INFO_UQ_METADATA)
- restructured the code as per sample code shared by Alex

V3: Split the UAPI patch from shadow_size_fn modifications
V4: Addressed review comments from UAPI review (Marek/Pierre-Eric)
    - Change the query name to AMDGPU_INFO_UQ_FW_AREAS
    - remove unused inpur parameter for AMDGPU_HW_IP*

link: https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/400/
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Arvind Yadav <arvind.yadav@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>