zink: use general-layout when blitting to/from same resource
This avoids a validator warning when for instance generating mipmaps. Fixes: d2bb63c8 ("zink: Use optimal layout instead of general. Reduces valid layer warnings. Fixes RADV image noise.") Reviewed-by:Mike Blumenkrantz <michael.blumenkrantz@gmail.com> Part-of: <mesa/mesa!5199>