[MMC] constify mmc_host_ops

Let drivers constify MMC host method operations tables,
moving them from ".data" to ".rodata".

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

include/linux/mmc/host.h

@@ -77,7 +77,7 @@ struct mmc_host {
 	struct device		*dev;
 	struct class_device	class_dev;
 	int			index;
-	struct mmc_host_ops	*ops;
+	const struct mmc_host_ops *ops;
 	unsigned int		f_min;
 	unsigned int		f_max;
 	u32			ocr_avail;