ARM: dts: msm: Move usb_otg node from dtsi files to dts files

As the configuration of usb_otg is not common among all the SKUI
platform, just move it into each dedicated dts files which need
this support.

Change-Id: I9f7f9ab2b3ada02ff469584515c9c5a8f954060f
Signed-off-by: Mao Jinlong <c_jmao@codeaurora.org>