arm64: defconfig: Enable Synopsys HDMI receiver

The Rockchip RK3588 has a built-in HDMI receiver block from
Synopsys. Let's enable the driver for it.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>