usb: musb: omap2430: don't loop indefinitely in interrupt.
When called during resume_irqs, omap2430_musb_set_vbus() is run with
interrupts disabled, In that case 'jiffies' never changes so the loop
can loop forever.
So impose a maximum loop count and add an 'mdelay' to ensure we wait
a reasonable amount of time for bit to be cleared.
This fixes a hang on resume.
Signed-of-by: NeilBrown <neilb@suse.de> Signed-off-by: Felipe Balbi <balbi@ti.com>