[Keyboard] Iris via support, Rev 3 updates (#4849)

* Add encoder support

* Add VIA support to Iris Rev. 3

* Update pinout and disable mouse keys to free up space

* Rollout VIA support to all Iris revisions

* Update default keymap

* Update vendor ID

keyboards/iris/iris.h

@@ -11,6 +11,7 @@
 #endif
 
 #include "quantum.h"
+#include "../../zeal60/zeal60_keycodes.h"
 
 // Used to create a keymap using only KC_ prefixed keys
 #define LAYOUT_kc( \