How to disable HDMI HDCP on AOSP?

I’m using AOSP build on HiKey960 board and trying to capture screen with AverMedia grabber from HDMI cable but it says “No signal” and it seems to be because HDCP is enabled.

So the main question: how to disable HDCP?

Can it be done with kernel command (BOARD_KERNEL_CMDLINE) in mk file?