x86/cpufeature.h: Reformat x86 feature macros

In each X86 feature macro definition, add one space in front of the word
number which is a one-digit number currently.

The purpose of reformatting the macros is to align one-digit and two-digit
word numbers.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1401387164-43416-2-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>