kbuild: remove scripts/basic/% build target

This build rule was introduced by commit cd05e6bd ("[PATCH]
kbuild: fix split-include dependency") to handle the dependency of
scripts/basic/split-include.

Now, fixdep is the only tool in scripts/basic/, and this rule is
no longer used.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Makefile

@@ -477,9 +477,6 @@ scripts_basic:
 	$(Q)$(MAKE) $(build)=scripts/basic
 	$(Q)rm -f .tmp_quiet_recordmcount
 
-# To avoid any implicit rule to kick in, define an empty command.
-scripts/basic/%: scripts_basic ;
-
 PHONY += outputmakefile
 # outputmakefile generates a Makefile in the output directory, if using a
 # separate output directory. This allows convenient use of make in the