i965/blit: Break blits into chunks in set_alpha_to_one

v2: Properly handle linear blit alignment restrictions

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
1 file changed