mmc: dw_mmc: remove setup_clock callback

Now, no dw_mmc variant drivers use this callback, let's
remove it.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.h

@@ -277,7 +277,6 @@ struct dw_mci_slot {
  * dw_mci driver data - dw-mshc implementation specific driver data.
  * @caps: mmc subsystem specified capabilities of the controller(s).
  * @init: early implementation specific initialization.
- * @setup_clock: implementation specific clock configuration.
  * @set_ios: handle bus specific extensions.
  * @parse_dt: parse implementation specific device tree properties.
  * @execute_tuning: implementation specific tuning procedure.
@@ -289,7 +288,6 @@ struct dw_mci_slot {
 struct dw_mci_drv_data {
 	unsigned long	*caps;
 	int		(*init)(struct dw_mci *host);
-	int		(*setup_clock)(struct dw_mci *host);
 	void		(*set_ios)(struct dw_mci *host, struct mmc_ios *ios);
 	int		(*parse_dt)(struct dw_mci *host);
 	int		(*execute_tuning)(struct dw_mci_slot *slot, u32 opcode);