hwc: Skip dss composition for single NV12 layer

In single NV12 layer case, it is being assigned to GFX pipe
which cannot do color-conversion. Skipping DSS composition in
this scenario.

Change-Id: I2548f2c27cf1ae0ece6350729f606ecea6fa038b
Signed-off-by: Gowtham Tammana <g-tammana@ti.com>
1 file changed