USB: musb: Remove unused inline function

It is never used, so can remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200715031204.17308-1-yuehaibing@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/musb_host.h

@@ -97,7 +97,6 @@ static inline void musb_host_tx(struct musb *musb, u8 epnum)	{}
 static inline void musb_host_rx(struct musb *musb, u8 epnum)	{}
 static inline void musb_root_disconnect(struct musb *musb)	{}
 static inline void musb_host_resume_root_hub(struct musb *musb)	{}
-static inline void musb_host_poll_rh_status(struct musb *musb)	{}
 static inline void musb_host_poke_root_hub(struct musb *musb)	{}
 static inline int musb_port_suspend(struct musb *musb, bool do_suspend)
 {