usb: musb: blackfin: add bfin_fifo_offset in bfin_ops

The function bfin_fifo_offset is defined but not used:

drivers/usb/musb/blackfin.c:36:12: warning: ‘bfin_fifo_offset’ defined
but not used [-Wunused-function]
 static u32 bfin_fifo_offset(u8 epnum)
             ^~~~~~~~~~~~~~~~

Adding bfin_fifo_offset to bfin_ops fixes this warning and allows musb
core to call this function instead of default_fifo_offset.

Fixes: cc92f6818f6e ("usb: musb: Populate new IO functions for blackfin")
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/blackfin.c

@@ -469,6 +469,7 @@ static const struct musb_platform_ops bfin_ops = {
 	.init		= bfin_musb_init,
 	.exit		= bfin_musb_exit,
 
+	.fifo_offset	= bfin_fifo_offset,
 	.readb		= bfin_readb,
 	.writeb		= bfin_writeb,
 	.readw		= bfin_readw,