Having worked on the OpenRISC project for ~4 years I thought I could share some insights here, as the licensing question pops up all the time.
The RTL for OpenRISC and most of the peripheral controllers that are used are licensed under LGPL, not GPL. While we all know that this is a software license with some concepts that don't translate well to hardware, the consensus is that LGPL means that you are obliged to shared modifications of the LGPL-licensed core, while GPL-licensed RTL would require the whole SoC to be GPL.
This is a view that we in the OpenRISC community share with the Open Source Hardware developers at CERN and other groups. This has also been tried by IP lawyers for a large company that wanted to use OpenRISC about ten years ago.
As for ASIC implementations it could be worth mentioning that there are ASICs running or1200 (the original LPGL-licensed OpenRISC implementation) in Samsung Digital TVs, in some of the Allwinner SoCs, Zigbee ASICs and other places, so it has been done many times over the years