ARM: shmobile: lager dts: Enable Quad SPI transfers for the SPI FLASH

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7790-lager.dts

@@ -243,6 +243,8 @@ flash: flash@0 {
 		compatible = "spansion,s25fl512s";
 		reg = <0>;
 		spi-max-frequency = <30000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
 		m25p,fast-read;
 
 		partition@0 {