target-s390x: Fix build for non-linux hosts

linux/kvm.h is not always available for compilation.

Neither linux/kvm.h nor kvm.h are needed, so remove both
which also fixes the build problem for non-linux hosts.

Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

target-s390x/helper.c

diff --git a/target-s390x/helper.c b/target-s390x/helper.c
index c79af46..745d8c5 100644
--- a/target-s390x/helper.c
+++ b/target-s390x/helper.c
@@ -28,11 +28,6 @@
 #include "qemu-common.h"
 #include "qemu-timer.h"
 
-#if !defined(CONFIG_USER_ONLY)
-#include <linux/kvm.h>
-#include "kvm.h"
-#endif
-
 //#define DEBUG_S390
 //#define DEBUG_S390_PTE
 //#define DEBUG_S390_STDOUT