ARM: dts: Add Exynos5250 Snow Rev5+ support on exynos5250-snow-rev5

There are 2 revisions of the Exynos5250 Snow Chromebook that were
shipped: Rev4 and Rev5. The only difference between these 2 revisions
is the codec, Rev4 has a max98095 codec while Rev5 has a max98090.

Mainline only supports Rev4 so this patch moves the common device
nodes to a DTSI file and adds a DTS for the Exynos5250 Snow Rev5.

The Snow Rev5 DTS is based on the DTS found in the ChromiumOS 3.8
tree.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Kukjin Kim <kgene@kernel.org>