kconfig: qconf: compile moc object separately

Currently, qconf.moc is included from qconf.cc but they can be compiled
independently.

When you modify qconf.cc, qconf.moc does not need recompiling.

Rename qconf.moc to qconf-moc.cc, and split it out as an independent
compilation unit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/scripts/kconfig/.gitignore b/scripts/kconfig/.gitignore
index 12a67fd..c3d537c 100644
--- a/scripts/kconfig/.gitignore
+++ b/scripts/kconfig/.gitignore
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-*.moc
+/qconf-moc.cc
 *conf-cfg
 
 #
diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index a5e770e..52b59bf9 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -181,21 +181,22 @@
 
 # qconf: Used for the xconfig target based on Qt
 hostprogs	+= qconf
-qconf-cxxobjs	:= qconf.o
+qconf-cxxobjs	:= qconf.o qconf-moc.o
 qconf-objs	:= images.o $(common-objs)
 
 HOSTLDLIBS_qconf	= $(shell . $(obj)/qconf-cfg && echo $$libs)
 HOSTCXXFLAGS_qconf.o	= $(shell . $(obj)/qconf-cfg && echo $$cflags)
+HOSTCXXFLAGS_qconf-moc.o = $(shell . $(obj)/qconf-cfg && echo $$cflags)
 
-$(obj)/qconf.o: $(obj)/qconf-cfg $(obj)/qconf.moc
+$(obj)/qconf.o: $(obj)/qconf-cfg
 
 quiet_cmd_moc = MOC     $@
-      cmd_moc = $(shell . $(obj)/qconf-cfg && echo $$moc) -i $< -o $@
+      cmd_moc = $(shell . $(obj)/qconf-cfg && echo $$moc) $< -o $@
 
-$(obj)/%.moc: $(src)/%.h $(obj)/qconf-cfg FORCE
+$(obj)/qconf-moc.cc: $(src)/qconf.h $(obj)/qconf-cfg FORCE
 	$(call if_changed,moc)
 
-targets += qconf.moc
+targets += qconf-moc.cc
 
 # gconf: Used for the gconfig target based on GTK+
 hostprogs	+= gconf
diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 4a61612..bb0a0bd 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -23,7 +23,6 @@
 #include "lkc.h"
 #include "qconf.h"
 
-#include "qconf.moc"
 #include "images.h"