Merge tag 'vmwgfx-fixes-2021-04-14' of gitlab.freedesktop.org:zack/vmwgfx into drm-fixes

vmwgfx fixes for regressions in 5.12

Here's a set of 3 patches fixing ugly regressions
in the vmwgfx driver. We broke lock initialization
code and ended up using spinlocks before initialization
breaking lockdep.
Also there was a bit of a fallout from drm changes
which made the core validate that unreferenced buffers
have been unpinned. vmwgfx pinning code predates a lot
of the core drm and wasn't written to account for those
semantics. Fortunately changes required to fix it
are not too intrusive.
The changes have been validated by our internal ci.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/f7add0a2-162e-3bd2-b1be-344a94f2acbf@vmware.com