libhwc2.1 : Set destAquireFence only in case of Decon.

For virtual display the destination aquire fence should not be
set to -1, as it will not allow the acrylicAquireFenceFd to be
updated. Conditional check for decon before setting aquire fence
is added.

Change-Id: I3a70a2fdc92f1793646f55d2982e159670c94696
Signed-off-by: Alan Gaurav Marti <alan.marti@samsung.com>
1 file changed