ARM: dts: msm: add 4.2.0 dp phy version on SDM855

Dp phy register programming sequence and some register
offsets changed on dp phy 4.2.0 version. Dp driver
switches to correct functionality based on pd phy version
indicated in device tree.
Patch sets 4.2.0 phy version and updates aux configuration
on SDM855.

Change-Id: Ieaad9b0b3e61c2503aa112deabb0bba0b01d8f37
Signed-off-by: Alexander Beykun <abeykun@codeaurora.org>