ib: show unified target based on $(TARGETID)

Instead of showing a slightly more readable target like
"ar71xx (Generic)" print the more generic format "ar71xx/genric"

Signed-off-by: Paul Spooren <mail@aparcar.org>

target/imagebuilder/files/Makefile

@@ -94,7 +94,7 @@ staging_dir/host/.prereq-build: include/prereq-build.mk
 	touch $@
 
 _call_info: FORCE
-	echo 'Current Target: "$(BOARD)$(if $(SUBTARGET), ($(BOARDNAME)))"'
+	echo 'Current Target: "$(TARGETID)"'
 	echo 'Default Packages: $(DEFAULT_PACKAGES)'
 	echo 'Available Profiles:'
 	echo; $(PROFILE_LIST)