usb: musb: pass platform_ops via platform_data

... then we don't need to export any symbols
from glue layer to musb_core.

Signed-off-by: Felipe Balbi <balbi@ti.com>

include/linux/usb/musb.h

@@ -126,6 +126,9 @@ struct musb_hdrc_platform_data {
 
 	/* Architecture specific board data	*/
 	void		*board_data;
+
+	/* Platform specific struct musb_ops pointer */
+	const void	*platform_ops;
 };