egl/glx: Remove egl_glx driver

Mesa now has a real, feature-rich EGL implementation on X11 via xcb.
Therefore I believe there is no longer a practical need for the egl_glx
driver.

Furthermore, egl_glx appears to be unmaintained.  The most recent
nontrivial commit to egl_glx was 6baa5f1 on 2011-11-25.

Tested by running weston-smoke in windowed Weston on X with i965.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Kristian Høgsberg <krh@bitplanet.net>

src/egl/main/egldriver.c

@@ -72,9 +72,6 @@ const struct {
 #endif
 #ifdef _EGL_BUILT_IN_DRIVER_DRI2
    { "egl_dri2", _eglBuiltInDriverDRI2 },
-#endif
-#ifdef _EGL_BUILT_IN_DRIVER_GLX
-   { "egl_glx", _eglBuiltInDriverGLX },
 #endif
    { NULL, NULL }
 };