kconfig: include common Kconfig files from top-level Kconfig

Instead of duplicating the source statements in every architecture just
do it once in the toplevel Kconfig file.

Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of
the top-level Kconfig into arch/Kconfig so that don't violate ordering
constraits while keeping a sensible menu structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/init/Kconfig b/init/Kconfig
index 1e69f93..283f6bc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1721,10 +1721,10 @@
 config TRACEPOINTS
 	bool
 
-source "arch/Kconfig"
-
 endmenu		# General setup
 
+source "arch/Kconfig"
+
 config RT_MUTEXES
 	bool