ARM: dts: msm: Remove USB async IRQ from msm8936 simulator

This change is required as "USB: phy-msm-usb: Enable USB Interrupt only
if ASYNC IRQ is not present" disables usb interrupt as simulator is not
simulating async irq, but it is present in dt.

Change-Id: Ifbbd94a359830fb095ef973c878ac1527afbfce5
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>