soc-qcom-sc7280: replace with soc-qcom

With the addition of 81voltd the difference between soc-qcom-sc7280 and soc-qcom shrank¹. With the unreliable hardware en- and decoder and a workaround in soc-qcom², it would shrink even further.

As such, it makes sense to replace the former with the latter.

With q6voiced and a call audio wireplumber config, soc-qcom adds two more things untestable on the two devices currently using soc-qcom-sc7280 (Fairphone 5 and Shiftphone 8).

Besides that, it is only a UPower.conf replacing suspend with shutdown in case of critically low battery levels and setting the low level from 20 % to 10 %, which makes sense on these two devices as well.

¹ as noted here: !7044 (comment 501998)
² suggested here: !7107 (comment 508712)

/cc @rmader