m32r: fix build failure

m32r: fix build failure

m32r allmodconfig build was failing with the error:

  ERROR: "smp_flush_cache_all" [drivers/misc/lkdtm.ko] undefined!

lkdtm driver at drivers/misc is using flush_icache_range() which for
m32r is defined as smp_flush_cache_all() if CONFIG_SMP is defined.  But
as smp_flush_cache_all() was not exported so the build was failing with
the error of undefined symbol.

Link: http://lkml.kernel.org/r/1464001182-8329-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>