imx: imx8qm-rom7720: switch to binman

Switch to use binman to pack images

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
diff --git a/doc/board/advantech/imx8qm-rom7720-a1.rst b/doc/board/advantech/imx8qm-rom7720-a1.rst
index bd4be1d..953cf01 100644
--- a/doc/board/advantech/imx8qm-rom7720-a1.rst
+++ b/doc/board/advantech/imx8qm-rom7720-a1.rst
@@ -57,8 +57,7 @@
      $ export ATF_LOAD_ADDR=0x80000000
      $ export BL33_LOAD_ADDR=0x80020000
      $ make imx8qm_rom7720_a1_4G_defconfig
-     $ make u-boot.bin
-     $ make flash.bin
+     $ make
 
 Flash the binary into the SD card
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