tools: mkimage: add support for Vybrid image format

This format can be flashed directly at address 0 of
the NAND FLASH, as it contains all necessary headers.

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
diff --git a/Makefile b/Makefile
index c67cc99..e9cdf9a 100644
--- a/Makefile
+++ b/Makefile
@@ -845,6 +845,12 @@
 %.imx: %.bin
 	$(Q)$(MAKE) $(build)=arch/arm/imx-common $@
 
+%.vyb: %.imx
+	$(Q)$(MAKE) $(build)=arch/arm/cpu/armv7/vf610 $@
+
+quiet_cmd_copy = COPY    $@
+      cmd_copy = cp $< $@
+
 u-boot.dtb: dts/dt.dtb
 	$(call cmd,copy)