tools/nolibc: MIPS: add support for N64 and N32 ABIs

tools/nolibc: MIPS: add support for N64 and N32 ABIs

Add support for the MIPS 64bit N64 and ILP32 N32 ABIs.

In addition to different byte orders and ABIs there are also different
releases of the MIPS architecture. To avoid blowing up the test matrix,
only add a subset of all possible test combinations.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Link: https://lore.kernel.org/r/20250623-nolibc-mips-n32-v3-4-6ae2d89f4259@weissschuh.net