usb: musb: drop the set_clock magic

now that platform glue layer handles
clock completely, that function is completely
useless for us. Drop it.

Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/musb/musb_core.h

···
 	u8 board_mode;		/* enum musb_mode */
 	int			(*board_set_power)(int state);
 
-	int			(*set_clock)(struct clk *clk, int is_active);
-
 	u8			min_power;	/* vbus for periph, in mA/2 */
 
 	bool			is_host;

include/linux/usb/musb.h

···
 	/* Power the device on or off */
 	int		(*set_power)(int state);
 
-	/* Turn device clock on or off */
-	int		(*set_clock)(struct clk *clock, int is_on) __deprecated;
-
 	/* MUSB configuration-specific details */
 	struct musb_hdrc_config	*config;