renderer-gl: Avoid retrieving the EGL image it direct_display flag was set

renderer-gl: Avoid retrieving the EGL image it direct_display flag was set

As we avoid importing the buffer in the GPU, when attaching the buffer
we'll not have a valid image to retrieve it from, and as such we'll
avoid touching and setting the surface state shader.

This adds also 'direct_display' to the surface state and with it, sets the
surface state 'direct_display' member whenever the imported buffer will
have the direct-display member set.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>