[MX8M][C72N][TANARO] Replaced mkimage_uboot

The mkimage_uboot is build by the NXP/i.MX U-Boot itself.
To support different versions across our platforms we replace
the fixed binary version by a link to the one build by U-Boot.

mk_imximage

@@ -57,6 +57,7 @@ elif [[ "$BOARD" == "c72n" ]]; then
         [ -e iMX8M/flash.bin ] && rm iMX8M/flash.bin
         cd iMX8M/
         ln -sf bl31-imx8mn.bin bl31.bin
+        ln -sf ../../mkimage mkimage_uboot
         ln -sf ../../../arch/arm/dts/seco-imx8mn-c72.dtb imx8mn-ddr4-evk.dtb
         ln -sf ../../../u-boot.bin u-boot.bin
         ln -sf ../../../u-boot-nodtb.bin .
@@ -91,6 +92,7 @@ then
 	cd iMX8M/
 	ln -sf bl31-imx8mm_tanaro.bin bl31.bin
 	ln -sf tee-imx8mm_tanaro.bin tee.bin
+	ln -sf ../../mkimage mkimage_uboot
 	ln -sf ../../../arch/arm/dts/kuk-trizeps8mini.dtb evk.dtb
 	ln -sf ../../../u-boot.bin .
 	ln -sf ../../../u-boot-nodtb.bin .