ENGR00215884-1 MX6 SabreSD:Refine OV mipi camera reset sequence

ENGR00215884-1 MX6 SabreSD:Refine OV mipi camera reset sequence

This patch refines OV mipi camera reset sequence according to
OV's recommendation:
reset --------------------|_____|----------------
                        ->| 1ms |<-
pwdn  ----------|_________________________|------
              ->|   5ms   |<- ->|   5ms   |<-
    ->|   5ms   |<-

This change makes the OV mipi camera be at a correct status
after reset, otherwise, the wrong status of OV mipi camera
will reduce the ~2.78V analog camera power to ~2.3V, which
causes random thin colorful lines on OV5642 CSI camera image
as OV5642 CSI camera uses the same analog power.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
(cherry picked from commit 9e78895d8856651b769908e63d4ebc514314eeaa)