configs: sopine-baseboard: Enable SPI-FLASH

SoPine has winbond SPI-FLASH, so enable the same in defconfig
and add aliases for spi0 in -u-boot.dtsi

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

arch/arm/dts/sun50i-a64-sopine-baseboard-u-boot.dtsi

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+#include "sunxi-u-boot.dtsi"
+
+/ {
+	aliases {
+		spi0 = &spi0;
+	};
+};