package/mesa3d: fix uClibc build

Moved the util/compiler.h include to util/macros.h due to upstream
commit which added static_assert() to src/util/macros.h
https://cgit.freedesktop.org/mesa/mesa/commit/src/util/macros.h?h=22.2&id=f1023571e8ce7ccb6ec7bc115240cb76aef3e5e5

Please note that this patch can be removed when buildroot toolchains
are updated to uClibc 1.0.42:
https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?h=v1.0.42&id=03fbd941e943976bb92cb392882c2ff7ec218704

Fixes:
http://autobuild.buildroot.net/results/a55/a55d6980faad8b5063f8f4f8b89467061d44a2ae/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>