mesa: Build separate GLU library

Mesa has removed GLU from the core tree upstream, so remove it from the
Mesa build and add the separate tarball as a new recipe.

(From OE-Core rev: 4395691a44b198ba0b9a969cbade669e8de07a4f)

Signed-off-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 662a445b30af4d7538c3e7081dd9403acd006938)

Conflicts:

	meta/recipes-graphics/mesa/mesa-common.inc