mmc: sdhci: add hooks for setting UHS in platform specific code

Allow platform specific code to set UHS registers if
implementation requires speciial platform specific handling

Signed-off-by: Philip Rakity <prakity@marvell.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 8ea11b7..7e28eec 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -270,6 +270,8 @@
 	unsigned int    (*get_ro)(struct sdhci_host *host);
 	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);
+
 };
 
 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS