svga: Use utility functions to help determine whether we can use copy_region

svga: Use utility functions to help determine whether we can use copy_region

It seems like the SVGA tests are in general more stringent than the utility
tests, but they also miss some blitter features like filters and window
rectangles, and if new blitter features are added in the future, it might
be possible that we forget adding tests for those.

So in addition to the SVGA tests, use the utility tests to restrict the
situations where we can use copy_region.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>