mmc: davinci: Add support for set_power callback

Some devices connected to the MMC bus are power controlled by external
means. For instance, an SDIO device may be powered down/up by an
external gpio line.

In order to avoid toggling power from within the MMC host driver, add a
set_power callback function, which will be called by set_ios upon
powering down/up.

Signed-off-by: Ido Yariv <ido@wizery.com>
CC: Chris Ball <cjb@laptop.org>
Acked-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
diff --git a/arch/arm/mach-davinci/include/mach/mmc.h b/arch/arm/mach-davinci/include/mach/mmc.h
index d4f1e96..5ba6b22 100644
--- a/arch/arm/mach-davinci/include/mach/mmc.h
+++ b/arch/arm/mach-davinci/include/mach/mmc.h
@@ -12,6 +12,9 @@
 	/* get_cd()/get_wp() may sleep */
 	int	(*get_cd)(int module);
 	int	(*get_ro)(int module);
+
+	void	(*set_power)(int module, bool on);
+
 	/* wires == 0 is equivalent to wires == 4 (4-bit parallel) */
 	u8	wires;