intel: use _mesa_meta_Clear with OpenGL ES 1.1 v2

intel: use _mesa_meta_Clear with OpenGL ES 1.1 v2

Patch changes i915 and i965 drivers to use fixed function version of
meta clear when running on ES 1.1. This fixes rendering errors seen with
Google Maps, Angry Birds and Gallery3D on Android platform.

Change 88128516d43be5d25288ff5b64db63cda83c04b3 exposes all extensions
internally to be available independent of GL flavour, therefore check
against ARB_fragment_shader does not work.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50333
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>