[MIPS] Use ARRAY_SIZE macro when appropriate

arch/mips/arc/identify.c

arch/mips/jmr3927/rbhma3100/setup.c

arch/mips/mips-boards/atlas/atlas_int.c

arch/mips/mips-boards/malta/malta_int.c

arch/mips/pci/fixup-vr4133.c