ARM: dts: msm: Add USB VBUS configuration for MSM8996 CDP_AU

USB 5V VBUS can be switched independently for the two USB
instances on the CDP_AU board. Add the PM8994 GPIO/MPP
configurations and expose them as usb_vbus_vreg,
usb_otg_switch and usb2_otg_switch regulators that can be
controlled by the USB controller device instances.

Also fix up the &usb3 node. Due to commit c51ea2bb
("ARM: dts: msm: Add GIC ITS extensions for 8996") changing
the size of address-cells for the &intc node, the interrupt-map
property needs to be updated to the new format. Also update
the correct IRQ numbers and add the missing ss_phy_irq to
sync up with the msm8996 SOC DT definition. Finally, remove
the unused vdda supply entries as well.

CRs-fixed: 971957
Change-Id: Id53f0a54e16b194bc12e57fac3e52efc43ebdc6c
Signed-off-by: Jack Pham <jackp@codeaurora.org>