kbuild: Extend defconfig field size from 24 to 27

There are 6 defconfigs with names longer than 24 characters, breaking
alignment in "make help".

The "winner" is "ecovec24-romimage_defconfig", counting in at 27
characters.

Extend the defconfig field size to 27 to restore alignment.
Don't use a larger value, to not encourage people to create even longer
defconfig names.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Makefile

@@ -1512,7 +1512,7 @@ help:
 	@echo  ''
 	@$(if $(boards), \
 		$(foreach b, $(boards), \
-		printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
+		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
 		echo '')
 	@$(if $(board-dirs), \
 		$(foreach b, $(board-dirs), \