video: ARM CLCD: support pads connected in reverse order

There are CLCDs connected with the pads in BGR rather than RGB
order. It really doesn't matter since the CLCD has a flag and
a bit to switch the position of the RGB and BGR components.
This is needed to put something logical into the
arm,pl11x,tft-r0g0b0-pads property of the device tree on the
Nomadik which will then be <16 8 0>.

Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>