x86, intel-mid: Add Merrifield platform support

This code was partially based on Mark Brown's previous work.

Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Link: http://lkml.kernel.org/r/1387224459-25746-4-git-send-email-david.a.cohen@linux.intel.com
Signed-off-by: Fei Yang <fei.yang@intel.com>
Cc: Mark F. Brown <mark.f.brown@intel.com>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>