mmc: add MMC_QUIRK_DISABLE_CD

006ebd5d introduced sdio_disable_cd(), which disconnects the pull-up
resistor on CD/DAT[3] (pin 1) of the card.

Make it possible to start using sdio_disable_cd() by introducing
MMC_QUIRK_DISABLE_CD.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 317a002..2a7e5497 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -129,6 +129,7 @@
 						/* (missing CIA registers) */
 #define MMC_QUIRK_BROKEN_CLK_GATING (1<<3)	/* clock gating the sdio bus will make card fail */
 #define MMC_QUIRK_NONSTD_FUNC_IF (1<<4)		/* SDIO card has nonstd function interfaces */
+#define MMC_QUIRK_DISABLE_CD	(1<<5)		/* disconnect CD/DAT[3] resistor */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
@@ -184,6 +185,11 @@
 	return c->quirks & MMC_QUIRK_BLKSZ_FOR_BYTE_MODE;
 }
 
+static inline int mmc_card_disable_cd(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_DISABLE_CD;
+}
+
 static inline int mmc_card_nonstd_func_interface(const struct mmc_card *c)
 {
 	return c->quirks & MMC_QUIRK_NONSTD_FUNC_IF;