Makefile: Add size check to the u-boot.itb make target

The make macro to check if the binary exceeds the board size limit is not
called. Make sure that is the case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/Makefile b/Makefile
index 4981a2e..7195219 100644
--- a/Makefile
+++ b/Makefile
@@ -1053,6 +1053,7 @@
 
 u-boot.itb: u-boot-nodtb.bin dts/dt.dtb $(U_BOOT_ITS) FORCE
 	$(call if_changed,mkfitimage)
+	$(BOARD_SIZE_CHECK)
 
 u-boot-spl.kwb: u-boot.img spl/u-boot-spl.bin FORCE
 	$(call if_changed,mkimage)