kconfig: include kernel/Kconfig.preempt from init/Kconfig

Almost all architectures include it.  Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index e4334f0..5b4f883 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -4,6 +4,7 @@
 	default y
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
+	select ARCH_NO_PREEMPT
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_AOUT
 	select HAVE_IDE