ARM: dts: msm: Add device tree for 8998 MTP with 4k display

The 4k display variant of the 8998 MTP has a new device subtype.
Creating a new device tree file with the default panel set to
4k command mode to support this MTP variant.

Change-Id: I1f1eee1baf2bfb1f452e724b55536674a9d6d973
Signed-off-by: Rajkumar Subbiah <rsubbia@codeaurora.org>