REORG: include: move common/ticks.h to haproxy/ticks.h

Nothing needed to be changed, there are no exported types.
diff --git a/src/backend.c b/src/backend.c
index 9f87a3c..a002bbe 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -22,7 +22,7 @@
 #include <haproxy/api.h>
 #include <haproxy/hash.h>
 #include <common/htx.h>
-#include <common/ticks.h>
+#include <haproxy/ticks.h>
 #include <haproxy/time.h>
 #include <haproxy/namespace.h>