meson: Allow building dri based EGL without GLX

It should be possible to build EGL without GLX, but the meson build
currently doesn't allow that because it too tightly couples glx and dri.
This patch eases dri and glx apart, so that EGL without GLX can be
built.

CC: Daniel Stone <daniels@collabora.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dylan Baker <dylan.c.baker@intel.com>
1 file changed