drm: atmel-hlcdc: add support for sama5d2 SoCs

drm: atmel-hlcdc: add support for sama5d2 SoCs

As the hardware description for this chip is the same as the sama5d4, we use
this SoC structures for layers and DC descriptions. Thus only 2 lines are added
to the atmel_hlcdc_of_match table.
The compatible string is already documented in the parent MFD driver's binding.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450178476-26284-10-git-send-email-boris.brezillon@free-electrons.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>