omap: Stalker board: switch over to gpio_set_debounce

Commit 48feb33747 arm: omap: switch over to gpio_set_debounce caused
"undefined reference to omap_set_gpio_debounce" build error.

The fix is to use the generic gpiolib function.

Cc: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/board-omap3stalker.c

@@ -538,9 +538,7 @@ static void ads7846_dev_init(void)
 		printk(KERN_ERR "can't get ads7846 pen down GPIO\n");
 
 	gpio_direction_input(OMAP3_STALKER_TS_GPIO);
-
+	gpio_set_debounce(OMAP3_STALKER_TS_GPIO, 310);
-	omap_set_gpio_debounce(OMAP3_STALKER_TS_GPIO, 1);
-	omap_set_gpio_debounce_time(OMAP3_STALKER_TS_GPIO, 0xa);
 }
 
 static int ads7846_get_pendown_state(void)