API: add vaQuerySurfaceAttributes().

API: add vaQuerySurfaceAttributes().

vaQuerySurfaceAttributes() is the recommended way to query the driver for
all surface attributes that are supported by the underlying hardware. This
is more useful than guessing the attribute values and testing them through
vaGetSurfaceAttributes().

The older vaGetSurfaceAttributes() function is hereby removed. However, the
relevant VA driver hook is kept for now, and will be removed/replaced for a
future update.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>