soc-camera: mt9t112: modify exiting conditions from standby mode

This polling is needed if camera is in standby mode, but current exiting
condition is inverted.

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>