lib/memcopy: use glibc version

the kernel's memcpy and memmove is very inefficient. But the glibc version is
quite fast, in some cases it is 10 times faster than the kernel version. So I
introduce some memory copy macros and functions of the glibc to improve the
kernel version's performance.

The strategy of the memory functions is:
1. Copy bytes until the destination pointer is aligned.
2. Copy words in unrolled loops.  If the source and destination are not
   aligned in the same way, use word memory operations, but shift and merge
   two read words before writing.
3. Copy the few remaining bytes.

Signed-off-by: Miao Xie <miaox*******>
lib/string: use glibc version

the performance of memcpy and memmove of the general version is very
inefficient, this patch improved them.

Signed-off-by: Miao Xie <miaox*******>
[PATCH] ARM: makefile: work around toolchain bug in recent versions of binutils

Recent upstream versions of binutils fail to assembler compressed/head.S
when passed the -march=all option:

http://lists.gnu.org/archive/html/bug-binutils/2011-04/msg00162.html

The recommended workaround from the tools folks is not to pass the
option, and instead let the assembler deduce the CPU type based on the
features used by the code.

Signed-off-by: Will Deacon <will.deacon@arm.com>