refactor(keys): Unify usage page.

* Remove need for separate `&cp` behavior, but
  keep it for now for backward compat.
* Refactor sensor inc/dec as well.

app/dts/bindings/behaviors/zmk,behavior-key-press.yaml

@@ -6,8 +6,3 @@ description: Key press/release behavior
 compatible: "zmk,behavior-key-press"
 
 include: one_param.yaml
-
-properties:
-  usage_page:
-    type: int
-    default: 0

app/dts/bindings/behaviors/zmk,behavior-sensor-rotate-key-press.yaml

@@ -13,9 +13,6 @@ properties:
     type: int
     required: true
     const: 2
-  usage_page:
-    type: int
-    default: 0
 
 sensor-binding-cells:
   - param1