arch/unicore32/kernel/ksyms.c: remove 2 export symbols to avoid compiling failure

'csum_partial' and 'csum_partial_copy_from_user' have already been
exported in "lib/", so need not export them again, or it will cause
compiling error.

The related error (with allmodconfig under unicore32):

    LD      vmlinux.o
  lib/built-in.o:(___ksymtab+csum_partial+0x0): multiple definition of `__ksymtab_csum_partial'
  arch/unicore32/kernel/built-in.o:(___ksymtab+csum_partial+0x0): first defined here
  lib/built-in.o:(___ksymtab+csum_partial_copy_from_user+0x0): multiple definition of `__ksymtab_csum_partial_copy_from_user'
  arch/unicore32/kernel/built-in.o:(___ksymtab+csum_partial_copy_from_user+0x0): first defined here
  make: *** [vmlinux] Error 1

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
arch: unicore32: kernel: ksyms: remove 'bswapsi2' and 'muldi3' to avoid compiling failure

After check the code, 'bswapsi2' and 'muldi3' are useless for
unicore32, so can remove them to avoid compiling failure.

The related error (with allmodconfig under unicore32):

    LD      init/built-in.o
  arch/unicore32/kernel/built-in.o:(___ksymtab+__muldi3+0x0): undefined reference to `__muldi3'
  arch/unicore32/kernel/built-in.o:(___ksymtab+__bswapsi2+0x0): undefined reference to `__bswapsi2'

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn>