package/mesa3d: Execute MESA3D_REMOVE_OPENGL_PC also for DRI configs lacking OpenGL

Mesa3d provides libgl only with DRI drivers and X.org enabled. Since

https://git.busybox.net/buildroot/commit/package/mesa3d/mesa3d.mk?id=f1894ec95728806e09405d26663e0ea371afaeab

DRI drivers can be enabled without X.org support, but mesa3d still does
not provide OpenGL support so we also need to remove the pkgconf files
in this case. A POST_INSTALL_*_HOOK is already present but needs to be
executed not only when DRI support was disabled but also with DRI en-
and X.org disabled.

Fixes
http://autobuild.buildroot.net/results/342/3420ad6aa8e1e8151bf11b43be2c97cbe1dbb400/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>