ARM: dts: imx: Convert i.MX8M flash.bin image generation to binman

Rework the flash.bin image generation such that it uses the new binman
nxp_imx8mimage etype. This way, the flash.bin is assembled in correct
order using plain binman, without any workarounds or sections assembled
in special DT node order.

Reviewed-By: Tim Harvey <tharvey@gateworks.com>
Tested-By: Tim Harvey <tharvey@gateworks.com> # imx8mm_venice
Tested-by: Fabio Estevam <festevam@gmail.com> # imx8mm-evk and imx8mn-evk
Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/arch/arm/dts/imx8mq-librem5-r4-u-boot.dtsi b/arch/arm/dts/imx8mq-librem5-r4-u-boot.dtsi
index e3341a4..1a4568d 100644
--- a/arch/arm/dts/imx8mq-librem5-r4-u-boot.dtsi
+++ b/arch/arm/dts/imx8mq-librem5-r4-u-boot.dtsi
@@ -11,14 +11,13 @@
 };
 
 &binman {
-	/delete-node/ signed-hdmi;
-
-	signed-hdmi {
-		filename = "signed_hdmi.bin";
-
-		signed-dp-imx8m {
-			filename = "signed_dp_imx8m.bin";
-			type = "blob-ext";
+	section {
+		nxp-imx8mimage {
+			section {
+				signed-hdmi-imx8m {
+					filename = "signed_dp_imx8m.bin";
+				};
+			};
 		};
 	};
 };