openrisc: Add architecture header files

arch/openrisc/include/asm/bitops.h

arch/openrisc/include/asm/bitops/ffs.h

arch/openrisc/include/asm/bitops/fls.h

arch/openrisc/include/asm/byteorder.h

arch/openrisc/include/asm/cache.h

arch/openrisc/include/asm/config.h

arch/openrisc/include/asm/errno.h

arch/openrisc/include/asm/global_data.h

arch/openrisc/include/asm/gpio.h

arch/openrisc/include/asm/io.h

arch/openrisc/include/asm/openrisc_exc.h

arch/openrisc/include/asm/posix_types.h

arch/openrisc/include/asm/processor.h

arch/openrisc/include/asm/ptrace.h

arch/openrisc/include/asm/spr-defs.h

arch/openrisc/include/asm/string.h

arch/openrisc/include/asm/system.h

arch/openrisc/include/asm/types.h

arch/openrisc/include/asm/u-boot.h

arch/openrisc/include/asm/unaligned.h