arm64: defconfig: Enable RT5659

Enable the RT5659 audio codec driver. Jetson AGX Xavier has RT5658 codec
which is compatible with this driver. This enables user to test external
audio.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Cc: Oder Chiou <oder_chiou@realtek.com>
Cc: Bard Liao <bardliao@realtek.com>