include: Add snapshot of sync and sw_sync headers in msm-4.9

Add snapshot of sync and sw_sync headers in msm-4.9 in linux and
uapi folder from msm-3.18 'commit f8b6819d0432 ("msm: ipa:
Fix to handle NULL pointer dereference")'.

Change-Id: Ic61c5e5cefbc6122b9b78117c61131929359283d
Signed-off-by: Shadab Naseem <snaseem@codeaurora.org>