Rename switcher.S to x86/switcher_32.S

lguest uses a "switcher" shim mapped high to bounce between host and
guest.  As lguest becomes less i386-centric, we separate this code
into a subdir.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/Makefile

@@ -3,8 +3,10 @@ obj-$(CONFIG_LGUEST_GUEST) += lguest_bus.o
 
 # Host requires the other files, which can be a module.
 obj-$(CONFIG_LGUEST)	+= lg.o
-lg-y := core.o hypercalls.o page_tables.o interrupts_and_traps.o \
-	segments.o io.o lguest_user.o switcher.o
+lg-y = core.o hypercalls.o page_tables.o interrupts_and_traps.o \
+	segments.o io.o lguest_user.o
+
+lg-$(CONFIG_X86_32) += x86/switcher_32.o
 
 Preparation Preparation!: PREFIX=P
 Guest: PREFIX=G

drivers/lguest/switcher.S → drivers/lguest/x86/switcher_32.S

@@ -48,7 +48,7 @@
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/page.h>
-#include "lg.h"
+#include "../lg.h"
 
 // We mark the start of the code to copy
 // It's placed in .text tho it's never run here