boot/rbcfg: drop Build/Prepare rule in favor of default one

Signed-off-by: Alexandru Ardelean <[email protected]>

package/boot/rbcfg/Makefile

@@ -26,11 +26,6 @@ define Package/rbcfg/description
  MikroTIK RB-4XX devices.
 endef
 
-define Build/Prepare
-	mkdir -p $(PKG_BUILD_DIR)
-	$(CP) ./src/* $(PKG_BUILD_DIR)/
-endef
-
 define Build/Configure
 endef