In connector atomic check, seamless vrr cannot be
determined since mode doesn't get populated by that time.
This change moves qsync validation from connector to encoder
atomic check to verify & handle modeset concurrencies.
Change-Id: Ia41bde4c05f98d8ba4cb39c18f2da1683cf9e5a3
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>