arm64: dts: renesas: rzg2lc-smarc-som: Enable 4-bit tx support

Enable 4-bit tx support for sbc node.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20231108172232.259301-3-biju.das.jz@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/rzg2lc-smarc-som.dtsi

@@ -241,6 +241,7 @@ flash@0 {
 		m25p,fast-read;
 		spi-max-frequency = <50000000>;
 		spi-rx-bus-width = <4>;
+		spi-tx-bus-width = <4>;
 
 		partitions {
 			compatible = "fixed-partitions";