fix: Fix error message when cannot find target board

[mirusu400]

Solved Problem

When we type wrong argument in first argument, the error said:

"Make target $@ not found. It either does not exist or $@ cannot be the first argument. Use '$(MAKE) help|list_config_targets' to get a list of all possible [configuration] targets."

But when typing make help|list_config_targets, it still not work.

Solution

• The command has been changed to $(MAKE) list_config_targets, so I changed Makefile too.