USB: S3C: Move usb-control.h to platform include

The usb-control.h is needed by ohci-s3c2410.c for both S3C24XX and S3C64XX
architectures, so move it to <plat/usb-control.h>

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>