mailbox: rockchip: remove MODULE_LICENSE in non-modules

Since commit 8b41fc44 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.
Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

drivers/mailbox/rockchip-mailbox.c

@@ -254,7 +254,6 @@ static struct platform_driver rockchip_mbox_driver = {
 
 module_platform_driver(rockchip_mbox_driver);
 
-MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");