mesa: Remove all traces of GL_OES_matrix_get

mesa: Remove all traces of GL_OES_matrix_get

I believe this extension was enabled by accident.  As far as I can tell,
there has never been any code in Mesa to actually support it.  Not only
that, this extension is only useful in the common-lite profile, and Mesa
does the common profile.

This "fixes" the piglit test oes_matrix_get-api.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Cc: "9.1 9.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>