msm8930: Add wilcoxltexx (Express 2) to build barrier

Change-Id: Ice6ea38ecc67a66ea745901572e9d5226f7eae31
msm8930: Move some device specific options to serrano-common

 * The Express 2 for example doesn't support this

Change-Id: Ib378f786a0a484989400cc1c70873f2177e2898a