board: omapl138_lcdk: add the mmc device to SPL

We don't have full device-tree support in SPL yet - add an appropriate
U_BOOT_DEVICE() to the board file.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

arch/arm/mach-davinci/Kconfig

@@ -14,6 +14,7 @@ config TARGET_OMAPL138_LCDK
 	bool "OMAPL138 LCDK"
 	select SOC_DA8XX
 	select SUPPORT_SPL
+	select SPL_BOARD_INIT
 
 config TARGET_LEGOEV3
 	bool "LEGO MINDSTORMS EV3"

board/davinci/da8xxevm/omapl138_lcdk.c

@@ -366,4 +366,13 @@ U_BOOT_DEVICE(omapl138_uart) = {
 	.name = "ns16550_serial",
 	.platdata = &serial_pdata,
 };
+
+U_BOOT_DEVICE(omapl138_mmc) = {
+	.name = "davinci_mmc",
+};
+
+void spl_board_init(void)
+{
+	davinci_configure_pin_mux(mmc0_pins, ARRAY_SIZE(mmc0_pins));
+}
 #endif