i965/skl: Extract the blit command setup in to a helper
i965/skl: Extract the blit command setup in to a helper

Signed-off-by: Anuj Phogat <e2026475996c48f0b97fd37e84129b3912980428@gmail.com>
Reviewed-by: Ben Widawsky <73675debcd8a436be48ec22211dcf44fe0df0a64@bwidawsk.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler