ARM: dts: msm: Disable secondary USB port for SDM845

Disable secondary USB port on mtp platform for SDM845, which is
not required for mobile platform. Else will see USB enumeration
failure on primary USB3.0 port due to sys.usb.controller being
overridden. Also Add DEBUG_CTRL1 register offset for QUSB2 PHY
to fix driver probe failure for secondary USB port.

Change-Id: Ie2c96ba15fcf80e01577d70a0dbcbf43e2fc3171
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>