msm: ipa4: 11ad Lan to Lan integration fixes

Keep ref count for SMMU mapped regs\data buffers, map\unmap
only when necessary.
Move uC Deinit channel to happen before SMMU unmap channel at
disconnect.
Add WIGIG events strings to debugfs.

Change-Id: I62f7f80ff8b9ac11b2fca48afb98f9797d783ec2
Signed-off-by: Amir Levy <alevy@codeaurora.org>