arm64: defconfig: Config that had RPMSG_CHAR now gets RPMSG_CTRL

In the commit 617d3293 ("rpmsg: Move the rpmsg control device
from rpmsg_char to rpmsg_ctrl"), we split the rpmsg_char driver in two.
By default give everyone who had the old driver enabled the rpmsg_ctrl
driver too.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>