drivers: mmc: omap_hsmmc: Fix IO Buffer on OMAP36xx

On the OMAP36xx/37xx the CONTROL_WKUP_CTRL register has
a field (bit 6) named GPIO_IO_PWRDNZ.  If 0, the IO buffers which
are related to GPIO_126, 127 and 129 are disabled. Some boards may
need this for MMC. After the PBIAS is configured, this bit should
be set high to enable these GPIO pins.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 0c07781..01d1dbf 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -131,6 +131,18 @@
 
 	  If unsure, say N.
 
+config MMC_OMAP36XX_PINS
+	bool "Enable MMC1 on OMAP36xx/37xx"
+	depends on OMAP34XX && MMC_OMAP_HS
+	help
+	  This enables extended-drain in the MMC/SD/SDIO1I/O and
+	  GPIO-associated I/O cells (gpio_126, gpio_127, and gpio_129)
+	  specific to the OMAP36xx/37xx using MMC1
+
+	  If you have a controller with this interface, say Y here.
+
+	  If unsure, say N.
+
 config SH_SDHI
 	bool "SuperH/Renesas ARM SoCs on-chip SDHI host controller support"
 	depends on RMOBILE