msm: video: wfd: Move WFD related files out of camera directory

The msm/ directory is intended for camera. Hence moving up the wfd/
directory one level higher and renaming it as msm_wfd/.

Change-Id: I9309ccfee91a04b6d55cf3be7ed88da15364b475
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>