config: imply apk-mbedtls with USE_APK
On top of the fixup to select apk-mbedtls when USE_APK is enabled from a
new config, also imply the package when enabling the config to catch
.config that are already init.
(Having both opkg and apk installed in a system is not a problem but if
USE_APK is used, APK presence in the system is mandatory)
Link: https://github.com/openwrt/openwrt/pull/15543
Signed-off-by: Christian Marangi <[email protected]>
Christian Marangi