m32r: fix build failure

m32r: fix build failure

The allmodconfig build of m32r is failing with the error:

  lib/mpi/mpih-div.o: In function 'mpihelp_divrem':
  mpih-div.c:(.text+0x40): undefined reference to 'abort'
  mpih-div.c:(.text+0x40): relocation truncated to fit:
	R_M32R_26_PCREL_RELA against undefined symbol 'abort'

The function 'abort' was never defined for the m32r architecture.

Create 'abort' as is done in other arch like 'arm' and 'unicore32'.

Link: http://lkml.kernel.org/r/1506727220-6108-1-git-send-email-sudip.mukherjee@codethink.co.uk
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>