video: fbdev: amba-clcd: Retire elder CLCD driver

All the functionality in this driver has been reimplemented
in the new DRM driver in drivers/gpu/drm/pl111/* and all
the boards using it have been migrated to use the DRM driver
with all configuration coming from the device tree.

I started the work to migrate the CLCD driver to DRM in
april 2017 and it took a little more than 3 years to do this
properly without leaving any platforms behind.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609200446.153209-2-linus.walleij@linaro.org