Broadwell sound issue

Hi all, total Linux/Fedora beginner here. I recently bought an NEC Ultrabook (it’s essentially NEC’s Japan market rebadging of a Lenovo Thinkpad Helix 2nd Gen) on which I tried to install Fedora. However, on installing Fedora 34 I found that there was no sound output (speakers or headphone) and no sound input (mic). Sound output and input works through bluetooth. I also tried Ubuntu and Cloudready, with same problem. I tried googling this and it seems that onboard sound was broken for Broadwell (5th Gen) intel chips in the Linux 5.2 kernel. Installing an old Ubuntu build with 5.1.x kernel supported this finding, as sound was working. Apparently though reported and recognised, this bug never got fixed. It seems that there is a workaround fix, which it said was to “Set CONFIG_SND_SOC_SOF_INTEL_TOPLEVEL to N.” However, unfortunately for me I have absolutely no idea how to do that. Without sound there is little point in my having Fedora installed, so I have currently restored the computer to Windows, but if anybody could help me with instructions of how to make this change then I would be extremely grateful and will reinstall Fedora 34 and give it a go.