ARM: dts: rockchip: Add IR receiver to RK3288 Radxa Rock 2 Square

Add support for the IR receiver as present on the Radxa Rock 2 Square
board.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>