network/config/swconfig: drop Build/Prepare rule in favor of default one

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

package/network/config/swconfig/Makefile

@@ -30,11 +30,6 @@ TARGET_CPPFLAGS := \
 	$(TARGET_CPPFLAGS) \
 	-I$(LINUX_DIR)/user_headers/include
 
-define Build/Prepare
-	mkdir -p $(PKG_BUILD_DIR)
-	$(CP) ./src/* $(PKG_BUILD_DIR)/
-endef
-
 define Build/Compile
 	CFLAGS="$(TARGET_CPPFLAGS) $(TARGET_CFLAGS)" \
 	$(MAKE) -C $(PKG_BUILD_DIR) \