mx53loco: Fix build error when CONFIG_VIDEO is disabled

mx53loco: Fix build error when CONFIG_VIDEO is disabled

The inclusion of LCD patch into mx53loco breaks the build when
CONFIG_VIDEO is disabled. Fix this by splitting the video
related stuff to a new file.

Also rename the function lcd_iomux to setup_iomux_lcd to make the
namings aligned with the other iomux functions.

Signed-off-by: Vikram Narayanan <[email protected]>
Signed-off-by: Anatolij Gustschin <[email protected]>
Cc: Fabio Estevam <[email protected]>
Cc: Stefano Babic <[email protected]>