move headers and connections into map dirs

ld_script.txt

@@ -368,7 +368,6 @@ SECTIONS {
         src/daycare.o(.rodata);
         data/data.o(.rodata.825EF0C);
         data/maps.o(.rodata);
-        data/connections.o(.rodata);
         src/fieldmap.o(.rodata);
         src/metatile_behavior.o(.rodata);
         data/metatile_behavior.o(.rodata);