cros: dts: peach: Refactor pit and pi dts/dtsi files

Now we have another variant for exynos5420 called exynos5422, lets
refactor the exsisting dts files to be used by both the SoCs.

This also adds a new dts file for exynos5422.

BRANCH=none
CQ-DEPEND=CL:*151263
BUG=chrome-os-partner:24688
TEST=built pit and pi boards. pi does not yet boot properly, pit boots
     all the way to Chrome OS login screen

Change-Id: I150682a5bcde3135fcff8ed4178671d02865c74c
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/181276
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/181820
5 files changed