usb: PHY: Make default behavior as No external resistance

USB HS PHYs no longer use external resistor for tuning
adjustment. Make this behavior default instead of
defining the no external resistance property in
device tree.

Change-Id: Ibd5de075fa44083cab1f89583cccfb2e1a43cac8
Signed-off-by: Elson Roy Serrao <eserrao@codeaurora.org>