Makefile.mk: make the overlapped error message more informative

Currently, if something is overlapped, you get this:
ERROR: Ramstage region _ramstage overlapped by: fallback/payload fallback/opensbi

This change prints out the start and end of the sections.

Change-Id: Ica8c05b63ed9bbd28e2d3daa4dc7c2f9d8da3f55
Signed-off-by: Ronald G Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81544
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

Makefile.mk

@@ -1388,7 +1388,7 @@ $(call add_intermediate, check-ramstage-overlaps)
 	        if [ -z $$rstart ]; then rstart=$$(($$y)) ; continue ; fi ; \
 	        rend=$$(($$y)) ; \
 	        if [ $$pstart -lt $$rend -a $$rstart -lt $$pend ]; then \
-	            echo "ERROR: Ramstage region _$$rname overlapped by:" \
+	            echo "ERROR: Ramstage region _$$rname@($$rstart,$$rend) overlapped by($$pstart,$$pend):" \
 	                 $(check-ramstage-overlap-files) ; \
 	            exit 1 ; \
 	        fi ; \