ARM: dts: Fix musb interrupt for device tree booting

Commit ad871c10

 (ARM: dts: OMAP: Add usb_otg and glue data to
OMAP3+ boards) added support for MUSB on omap3 for device tree,
but added the interrupts the wrong way probably as they were
copied from the omap4.dtsi file. On omap3 we have TI specific
interrupt controller, not GIC.

Fix this by specifying the interrupt following the TI INTC
binding.

Without this fix MUSB won't work as it is trying to use
irq0 instead of irq92.

Signed-off-by: Tony Lindgren <tony@atomide.com>