USB: s3c-hsotg: fix compilation problem

drivers/usb/gadget/s3c-hsotg.c: In function ‘s3c_hsotg_otgreset’:
drivers/usb/gadget/s3c-hsotg.c:2816: error: ‘MHZ’ undeclared (first use in this function)
drivers/usb/gadget/s3c-hsotg.c:2816: error: (Each undeclared identifier is reported only once
drivers/usb/gadget/s3c-hsotg.c:2816: error: for each function it appears in.)

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>