drm/udl: Drop unneeded alignment

The alignment of damaged area was needed for the original udlfb driver
that tried to trim the superfluous copies between front and backend
buffers and handle data in long int.  It's not the case for udl DRM
driver, hence we can omit the whole unneeded alignment, as well as the
dead code.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220908095115.23396-8-tiwai@suse.de