target-arm: Add AArch64 ELR_EL1 register.

Add the AArch64 ELR_EL1 register.

Note that this does not live in env->cp15: for KVM migration
compatibility we need to migrate it separately rather than
as part of the system registers, because the KVM-to-userspace
interface puts it in the struct kvm_regs rather than making
them visible via the ONE_REG ioctls.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
diff --git a/target-arm/machine.c b/target-arm/machine.c
index b9d9c0f..42b1c90 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -222,9 +222,9 @@
 
 const VMStateDescription vmstate_arm_cpu = {
     .name = "cpu",
-    .version_id = 14,
-    .minimum_version_id = 14,
-    .minimum_version_id_old = 14,
+    .version_id = 15,
+    .minimum_version_id = 15,
+    .minimum_version_id_old = 15,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
@@ -243,6 +243,7 @@
         VMSTATE_UINT32_ARRAY(env.banked_r14, ARMCPU, 6),
         VMSTATE_UINT32_ARRAY(env.usr_regs, ARMCPU, 5),
         VMSTATE_UINT32_ARRAY(env.fiq_regs, ARMCPU, 5),
+        VMSTATE_UINT64(env.elr_el1, ARMCPU),
         /* The length-check must come before the arrays to avoid
          * incoming data possibly overflowing the array.
          */