package/protobuf: remove target version of 'protoc'

The tool 'protoc' and its associated library libprotoc.so are only
needed during development, to convert a protocol buffer definition in the
associated code for a specific code language.

Buildroot does not officially support creating a development environment on
target, so remove these files to reduce disk usage by more than 1.5 MB
(stripped, uncompressed).

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/protobuf/protobuf.mk

@@ -36,5 +36,12 @@ ifeq ($(BR2_PACKAGE_ZLIB),y)
 PROTOBUF_DEPENDENCIES += zlib
 endif
 
+define PROTOBUF_REMOVE_UNNECESSARY_TARGET_FILES
+	rm -rf $(TARGET_DIR)/usr/bin/protoc
+	rm -rf $(TARGET_DIR)/usr/lib/libprotoc.so*
+endef
+
+PROTOBUF_POST_INSTALL_TARGET_HOOKS += PROTOBUF_REMOVE_UNNECESSARY_TARGET_FILES
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))