This is a port of
commit b49f184b
Author: Ben Collins <bcollins@ubuntu.com>
from udlfb to udl kms driver.

The driver was not using le16_to_cpu when reading keys from the vendor
descriptor, causing incorrect parsing. Mainly, sku_pixel_limit was not
being parsed on big-endian systems. This would result in a blank screen
on big-endian CPUs where the DL chips's max mode was smaller than the
monitor's native mode.
Signed-off-by: NDave Airlie <airlied@redhat.com>

This is an initial drm/kms driver for the displaylink devices.

Supports fb_defio,
supports KMS dumb interface
supports 24bpp via conversion to 16bpp, hw can do this better.
supports hot unplug using new drm core features.

On an unplug, it disables connector polling, unplugs connectors
from sysfs, unplugs fbdev layer (using Kay's API), drops all the
USB device URBs, and call the drm core to unplug the device.

This driver is based in large parts on udlfb.c so I've licensed
it under GPLv2.
Signed-off-by: NDave Airlie <airlied@redhat.com>