staging: mt7621-mmc: Remove unused field enable_cd_eirq from msdc_hw

The enable_cd_eirq() field of msdc_hw is never set and only once
checked for not being zero, so it is removed.
Signed-off-by: Christian Lütke-Stetzkamp <christian@lkamp.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-mmc/board.h

@@ -74,7 +74,6 @@ struct msdc_hw {
 	void (*disable_sdio_eirq)(void);
 
 	/* external cd irq operations */
-	void (*enable_cd_eirq)(void);
 	void (*disable_cd_eirq)(void);
 };
 

drivers/staging/mt7621-mmc/sd.c

@@ -2453,9 +2453,6 @@ static void msdc_enable_cd_irq(struct msdc_host *host, int enable)
 	N_MSG(CFG, "CD IRQ Eanable(%d)", enable);
 
 	if (enable) {
-		if (hw->enable_cd_eirq) { /* not set, never enter */
-			hw->enable_cd_eirq();
-		} else {
 		/* card detection circuit relies on the core power so that the core power
 		 * shouldn't be turned off. Here adds a reference count to keep
 		 * the core power alive.
@@ -2469,7 +2466,6 @@ static void msdc_enable_cd_irq(struct msdc_host *host, int enable)
 		sdr_set_bits(MSDC_PS, MSDC_PS_CDEN);
 		sdr_set_bits(MSDC_INTEN, MSDC_INTEN_CDSC);
 		sdr_set_bits(SDC_CFG, SDC_CFG_INSWKUP);  /* not in document! Fix me */
-		}
 	} else {
 		if (hw->disable_cd_eirq) {
 			hw->disable_cd_eirq();