dm: exynos: Make sure that GPIOs are requested

With driver model GPIOs must be requested before use. Make sure this is
done correctly.

(Note that the soft SPI part of universal is omitted, since this driver
is about to be replaced with a driver-model-aware version)

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/arm/cpu/armv7/exynos/pinmux.c

@@ -172,6 +172,9 @@ static int exynos5420_mmc_config(int peripheral, int flags)
 		 * this same assumption.
 		 */
 		if ((peripheral == PERIPH_ID_SDMMC0) && (i == (start + 2))) {
+#ifndef CONFIG_SPL_BUILD
+			gpio_request(i, "sdmmc0_vdden");
+#endif
 			gpio_set_value(i, 1);
 			gpio_cfg_pin(i, S5P_GPIO_OUTPUT);
 		} else {