egl/dri2: add support for optional extensions in dri2_bind_extensions()

Will allow us to reuse the function for optional extensions and fold a
bit of code.

v2: Make dri2_bind_extensions::optional flag an argument to
dri2_bind_extensions (Kristian).

Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
1 file changed