configs/mesa3d-ci: Introducing the configuration used by drm-ci and the Mesa3D farm

These configurations provide a tailored experience for running a GPU DUT, involving a number of development boards, Chromebooks, and regular PCs. The adjustments are primarily aimed at enabling seamless NFS boot without a ramdisk, ensuring all dependencies necessary for GPU testing are loaded in a timely manner.

Certain options such as WiFi support, DVB, etc., have been disabled to improve build times and reduce the size of the kernel and modules that need to be distributed to the DUT.

Another important aspect is to closely resemble the default architecture defconfigs as much as possible.

Signed-off-by: David Heidelberg <david@ixit.cz>