ARM: dts: msm: Enable extcon for USB2.0 on QCS405

SKU1 version of QCS405 has SMB charger and USB depends
on this for VBUS and ID notifications. So add
smb charger node as extcon for USB2.0 core.
Also add the vbus_dwc3-supply that enables the VBUS
boost in host mode.

Change-Id: I8c4bf50e979dc0d2638ac6761cbb0643a1822fea
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>