Move qemu-timer.h to include/qemu/timer.h

Note: upstream still puts qemu-timer.c in the top-level
directory, so no need to move it

Change-Id: I475309d6f0040b4fd2277e52a2526825c112e91f
diff --git a/qemu-timer.c b/qemu-timer.c
index 4e51dd3..353002c 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -53,7 +53,7 @@
 #include <mmsystem.h>
 #endif
 
-#include "qemu-timer.h"
+#include "qemu/timer.h"
 
 /* Conversion factor from emulated instructions to virtual clock ticks.  */
 int icount_time_shift;