ARM: dts: msm: Remove USB async IRQ from msm8916 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: Iaf44c089b843a16fafdf095a3e2633aef3c296b3
Signed-off-by: Tarun Gupta <tarung@codeaurora.org>