new helper: uaccess_kernel()

arch/alpha/include/asm/uaccess.h

arch/arc/include/asm/uaccess.h

arch/arm/include/asm/uaccess.h

arch/arm/lib/uaccess_with_memcpy.c

arch/blackfin/kernel/process.c

arch/c6x/kernel/sys_c6x.c

arch/cris/include/asm/uaccess.h

arch/m68k/include/asm/uaccess_mm.h

arch/metag/include/asm/uaccess.h

arch/mips/include/asm/checksum.h

arch/mips/include/asm/r4kcache.h

arch/mips/include/asm/uaccess.h

arch/mips/kernel/unaligned.c

arch/openrisc/include/asm/uaccess.h

arch/parisc/include/asm/futex.h

arch/parisc/lib/memcpy.c

arch/s390/include/asm/uaccess.h

arch/sparc/include/asm/uaccess.h

arch/sparc/include/asm/uaccess_32.h

arch/um/include/asm/uaccess.h