Merge pull request #6060 from neiljay/pr/add_mips32r2_common_v2

Makefile.buildtests

boards/mips-malta/Makefile

boards/mips-malta/Makefile.features

boards/mips-malta/Makefile.include

boards/mips-malta/include/board.h

boards/mips-malta/include/periph_conf.h

boards/mips-malta/malta.c

cpu/mips32r2_common/Makefile

cpu/mips32r2_common/Makefile.include

cpu/mips32r2_common/cpu.c

cpu/mips32r2_common/include/cpu.h

cpu/mips32r2_common/include/cpu_conf.h

cpu/mips32r2_common/include/periph_cpu.h

cpu/mips32r2_common/irq_arch.c

cpu/mips32r2_common/mips_dsp.S

cpu/mips32r2_common/mips_excpt_entry.S

cpu/mips32r2_common/periph/Makefile

cpu/mips32r2_common/periph/pm.c

cpu/mips32r2_common/periph/timer.c

cpu/mips32r2_common/thread_arch.c