HDMI multi-channel audio not working on Rock pi 4c

Hi, Manjaro has been working mostly great for me on the rock pi 4c. I do have a problem with HDMI audio output where it is limited to 2ch.

Here is the out of aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: hdmisound [hdmi-sound], device 0: ff8a0000.i2s-i2s-hifi i2s-hifi-0 [ff8a0000.i2s-i2s-hifi i2s-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0

Is that the limitation of the rockchip hardware? or is there a way of setting it up differently so that I could have more than two channels?