corrected writing to /boot/config.txt with sudo tee

[gigawatts]

Reason: https://stackoverflow.com/questions/84882/sudo-echo-something-etc-privilegedfile-doesnt-work

[maxbbraun]

Thanks!

[gigawatts]

Sure! The sed CMD to update cmdline.txt didn't work for me, had to add it manually, I'll try to diagnose that later.