qdev: remove print/parse methods from LostTickPolicy properties

Also generalize the code so that we can have more enum properties
in the future.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

qemu-common.h

@@ -255,6 +255,7 @@ typedef enum LostTickPolicy {
     LOST_TICK_DELAY,
     LOST_TICK_MERGE,
     LOST_TICK_SLEW,
+    LOST_TICK_MAX
 } LostTickPolicy;
 
 void tcg_exec_init(unsigned long tb_size);