ARM: dts: msm: Move SDM845 RUMI USB overrides to the include file

Move the RUMI-specific overrides for the USB nodes from the .dts
file to the .dtsi file. This allows sdm845-v2-rumi.dts to inherit
the same settings. Also remove the include for sdm845-usb.dtsi as
it now is part of the base SoC sdm845.dtsi.

Change-Id: I345b46317f0f060773b5e9589f2a84b493a55dd2
Signed-off-by: Jack Pham <jackp@codeaurora.org>