mmc: sh_mmcif: support generic card-detection

Extend the sh_mmcif driver to support GPIO card detection, provided by the
slot function module. The original .get_cd() platform callback is also
preserved for now.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/sh_mmcif.h b/include/linux/mmc/sh_mmcif.h
index 05f0e3d..c2f73cb 100644
--- a/include/linux/mmc/sh_mmcif.h
+++ b/include/linux/mmc/sh_mmcif.h
@@ -44,6 +44,8 @@
 	struct sh_mmcif_dma	*dma;		/* Deprecated. Instead */
 	unsigned int		slave_id_tx;	/* use embedded slave_id_[tr]x */
 	unsigned int		slave_id_rx;
+	bool			use_cd_gpio : 1;
+	unsigned int		cd_gpio;
 	u8			sup_pclk;	/* 1 :SH7757, 0: SH7724/SH7372 */
 	unsigned long		caps;
 	u32			ocr;