msm_11ad: Add 11ad platform driver

Platform driver used to handle msm specific platform
requirement for 11ad chipset connected to msm platform

Takes care of platform support like:
- power switch through dedicated GPIO
- bus frequency voting
- SMMU attachment

Change-Id: I09c54ea747a5b4e0688b1b7d96e83ef134bb4215
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>