omap: Beagle: no gpio_wp pin connection on xM

The omap3630 based BeagleBoard xM uses a MicroSD card slot with
no write protection.
Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
Acked-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/board-omap3beagle.c

@@ -272,7 +272,9 @@ static struct gpio_led gpio_leds[];
 static int beagle_twl_gpio_setup(struct device *dev,
 		unsigned gpio, unsigned ngpio)
 {
-	if ((omap3_beagle_get_rev() == OMAP3BEAGLE_BOARD_C1_3) ||
+	if (omap3_beagle_get_rev() == OMAP3BEAGLE_BOARD_XM) {
+		mmc[0].gpio_wp = -EINVAL;
+	} else if ((omap3_beagle_get_rev() == OMAP3BEAGLE_BOARD_C1_3) ||
 		(omap3_beagle_get_rev() == OMAP3BEAGLE_BOARD_C4)) {
 		omap_mux_init_gpio(23, OMAP_PIN_INPUT);
 		mmc[0].gpio_wp = 23;