USB: s3c2410 gadget: allow sharing of vbus irq

If another driver wants to claim the vbus pin, say
to notify the user of an connect/disconnect then allow
the IRQ to be shared by specifiying IRQ_SHARED in the
flags.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>