mesa: add AllowGLSLCrossStageInterpolationMismatch workaround

This fixes issues seen with certain versions of Unreal Engine 4 editor
and games built with that using GLSL 4.30.

v2: add driinfo_gallium change (Emil Velikov)

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97852
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103801


Acked-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit faccbaf3)
[Emil Velikov: resolve trivial conflicts]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

Conflicts:
	src/mesa/drivers/dri/i965/brw_context.c