Pass input device and time in key_handler callback

Move the modifiers to a input device getter function.
diff --git a/clients/resizor.c b/clients/resizor.c
index cd9bfdc..46d9cbf 100644
--- a/clients/resizor.c
+++ b/clients/resizor.c
@@ -128,8 +128,8 @@
 }
 
 static void
-key_handler(struct window *window, uint32_t key, uint32_t sym,
-	    uint32_t state, uint32_t modifiers, void *data)
+key_handler(struct window *window, struct input *input, uint32_t time,
+	    uint32_t key, uint32_t sym, uint32_t state, void *data)
 {
 	struct resizor *resizor = data;