st/xa: Add a function to check for supported formats

st/xa: Add a function to check for supported formats

Typically this was done by having a surface creation function fail if
the format was not supported.
However, in some situations when changing hardware surface formats,
it's desirable to do this check before attempting costly readback operations.

Also updated the surface_redefine interface.

Bump minor.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>