video: fbdev: fsl: Fix the sleep function for FSL DIU module

For deep sleep, the diu module will power off, when wake up
from the deep sleep, the registers need to be reinitialized.

Signed-off-by: Jason Jin <Jason.Jin@freescale.com>
Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com>
Acked-by: Timur Tabi <timur@tabi.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>