csky: abiv1: Fixup compile error

LD vmlinux.o
arch/csky/lib/string.o: In function `memmove':
string.c:(.text+0x108): multiple definition of `memmove'
lib/string.o:string.c:(.text+0x7e8): first defined here
arch/csky/lib/string.o: In function `memset':
string.c:(.text+0x148): multiple definition of `memset'
lib/string.o:string.c:(.text+0x2ac): first defined here
scripts/Makefile.vmlinux_o:68: recipe for target 'vmlinux.o' failed
make[4]: *** [vmlinux.o] Error 1

Fixes: e4df2d5e852a ("csky: Add C based string functions")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: <stable@vger.kernel.org>

csky: Fixup compile error

: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

csky: Fixup abiv1 memset error

Current memset implementation in abiv1 is wrong and it'll cause unalign
access. Just remove it and use the generic one. This patch will cause
performance degradation and we will improve it with a new design in next
patchset.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>

csky: Library functions

This patch adds string optimize codes and some auxiliary codes.

Signed-off-by: Chen Linfei <linfei_chen@c-sky.com>
Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>