mmc: sh_mmcif: Remove unused ->get_cd() platform callback

Removing the callback also enables us to remove the sh_mmcif_get_cd()
altogether, as we convert to use mmc_gpio_get_cd() to the same kind of
work.

Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

include/linux/mmc/sh_mmcif.h

@@ -32,7 +32,6 @@
  */
 
 struct sh_mmcif_plat_data {
-	int (*get_cd)(struct platform_device *pdef);
 	unsigned int		slave_id_tx;	/* embedded slave_id_[tr]x */
 	unsigned int		slave_id_rx;
 	bool			ccs_unsupported : 1;