ARM: dts: remove skip notifications for Liquid

It was deemed important to charge from the device port in liquid. To
achive that, remove the usbdetect node and the skip notification
property.

This way the USB PHY only listens to PMI for insertion/removal
notifications and can use PMI's type detection and commands for DP_DM
tristating.

Change-Id: Ib429d2abc6835c864bf889f31b0f2c2564762175
Signed-off-by: Bruce Levy <blevy@codeaurora.org>