nds32: lib: To use generic lib instead of libgcc to prevent the symbol undefined issue.

We can use the generic lib to fix these error because the symbol of
libgcc in toolchain is not exported.

ERROR: "__ucmpdi2" [fs/xfs/xfs.ko] undefined!
ERROR: "__ashrdi3" [fs/xfs/xfs.ko] undefined!
ERROR: "__lshrdi3" [fs/xfs/xfs.ko] undefined!
ERROR: "__ashldi3" [fs/ntfs/ntfs.ko] undefined!
...

Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>