drm/amdgpu: Add input fence to sync bo map/unmap

This patch adds input fences to VM_IOCTL for buffer object.
The kernel will map/unmap the BO only when the fence is signaled.
The UAPI for the same has been approved here:
https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/392



V2: Bug fix (Arvind)
V3: Bug fix (Arvind)
V4: Rename UAPI objects as per UAPI review (Marek)
V5: Addressed review comemnts from Christian
     - function should return error.
     - Add 'TODO' comment
     - The input fence should be independent of the operation.
V6: Addressed review comemnts from Christian
    - Release the memory allocated by memdup_user().
V7: Addressed review comemnts from Christian
    - Drop the debug print and add "return r;" for the error handling.

V11: Rebase
v12: Fix 32-bit holes issue in sturct drm_amdgpu_gem_va.
v13: Fix deadlock issue.
v14: Fix merge conflict.
v15: Fix review comment by renaming syncobj handles.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>