mmc: sdhci: add eMMC hardware reset support

Add an SDHCI operation for hardware reset and connect it to the
host controller operation.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 745c42f..7bd919c 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -273,7 +273,7 @@
 	void	(*platform_reset_enter)(struct sdhci_host *host, u8 mask);
 	void	(*platform_reset_exit)(struct sdhci_host *host, u8 mask);
 	int	(*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs);
-
+	void	(*hw_reset)(struct sdhci_host *host);
 };
 
 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS