ARM: dts: msm: Add secondary USB configuration for sm8150

Add support for second USB controller and PHYs on sm8150. Add
nodes for GPIO based extcon on CDP and MTP which is used to
notify cable connection status via VBUS and ID pins. Also use
secondary phandles for regulators which match the naming scheme
used in the power grid hardware documentation.

Leave the nodes disabled for now.

Change-Id: I0da14087011d5845a13fd956b6c5457265ec4fb4
Signed-off-by: Jack Pham <jackp@codeaurora.org>