MAINTAINERS: Add Liviu Dudau as maintainer for ARM HDLCD driver.

Update MAINTAINERS file for HDLCD driver.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: David S. Miller <davem@davemloft.net>

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>