video: msm: wfd: Reduce first frame latency in CFR mode

When we get the first frame, push it immediately to the encoder rather
than waiting for the timer to expire.

Change-Id: Icda6f5696d984ed683ee8a3395dfafefde0671c0
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>