linux-postmarketos-qcom-sc7280: upgrade to 6.6.0_rc4_git20231005 & lots of Fairphone 5 improvements

See commits for details.

I normally try to avoid getting -rc kernels into pmaports but I cannot hold off of so many nice improvements :) Will update to the final 6.6 release once that's out, but that'll take another 3 weeks or so.