ENGR00315894-70 iMX6SX:Video Update MXS LCDIF driver

ENGR00315894-70 iMX6SX:Video Update MXS LCDIF driver

Add a new interface "mxs_lcd_panel_setup" to setup fb parameters and
specifies the LCDIF controller for multiple controllers of iMX6SX.
Pass fb parameters via "videomode" env remains work if the new interface
is not called before video initialization.

Modify LCDIF clock interface "mxs_set_lcdclk" to support multiple
LCDIF controllers on iMX6SX.

Signed-off-by: Ye.Li <B37916@freescale.com>
Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
(cherry picked from commit d7f49b9378547c3a57b96bcdb907fc44616beb3d)
(cherry picked from commit e1343191b9de227c582847e7eeb5ce9238be0754)
(cherry picked from commit 9632ebeccc34d663e21bd19f2fe62de51947296e)
Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit 948c5c95e87a47bb3a80c8e67b67fe70e1e4a569)