kbuild: support simultaneous "make %config" and "make all"

Kbuild is supposed to support mixed targets. (%config and build targets)

But "make all" did nothing if it was run with configuration targets.
For example,

  $ LANG=C make defconfig all
    HOSTCC  scripts/basic/fixdep
    HOSTCC  scripts/kconfig/conf.o
    SHIPPED scripts/kconfig/zconf.tab.c
    SHIPPED scripts/kconfig/zconf.lex.c
    SHIPPED scripts/kconfig/zconf.hash.c
    HOSTCC  scripts/kconfig/zconf.tab.o
    HOSTLD  scripts/kconfig/conf
  *** Default configuration is based on 'x86_64_defconfig'
  #
  # configuration written to .config
  #
  make: Nothing to be done for `all'.

This commits allows "make %config all" and makes sure
mixed targets are built one by one in the given order.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Michal Marek <mmarek@suse.cz>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/mkmakefile

@@ -42,18 +42,11 @@ MAKEARGS += O=\$(if \$(patsubst /%,,\$(makedir)),\$(CURDIR)/)\$(patsubst %/,%,\$
 
 MAKEFLAGS += --no-print-directory
 
-.PHONY: all \$(MAKECMDGOALS)
+.PHONY: __sub-make \$(MAKECMDGOALS)
 
-all	:= \$(filter-out all Makefile,\$(MAKECMDGOALS))
+__sub-make:
+	\$(Q)\$(MAKE) \$(MAKEARGS) \$(MAKECMDGOALS)
 
-all:
-	\$(Q)\$(MAKE) \$(MAKEARGS) \$(all)
-
-Makefile:;
-
-\$(all): all
-	@:
-
-%/: all
+\$(filter-out __sub-make, \$(MAKECMDGOALS)): __sub-make
 	@:
 EOF