x86/platform/olpc: Fix resume handler build warning

x86/platform/olpc: Fix resume handler build warning

Fix:

  arch/x86/platform/olpc/olpc-xo15-sci.c:199:12: warning: ‘xo15_sci_resume’
  defined but not used [-Wunused-function]
   static int xo15_sci_resume(struct device *dev)
              ^

which I see in randconfig builds here.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161126142706.13602-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>