x86/x32: Fix the binutils auto-detect

Fix:

 arch/x86/Makefile:96: *** recipe commences before first target.  Stop.

Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: H. J. Lu <hjl.tools@gmail.com>
Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>