Revert "android: convert sync to fence api, v6"

This reverts commit 0f0d8406
("android: convert sync to fence api, v6"), these changes
are causing some random stability issues, reverting changes
until root cause is found.

Change-Id: I3d178829277acd8e237e0e8afc5e07b04322e1d9
[ingridg@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ingrid Gallardo <ingridg@codeaurora.org>