main/firmware-pine64-rtl8723bt: new aport
This partially reverts 06edc589 "main/firmware-pine64-rtl8723bt: drop (MR 5582)" because the linux-firmware fw breaks bluetooth on the pine64-pinephone 1.2b.
Specifically the cs_fw.bin from linux-firmware works but not the cs_xx_config.bin, so this restored package provides just the latter.
The original package provided bs_config.bin also. The BS is used by the pine64-a64-lts and pine64-dontbeevil, but I don't have those devices to know for sure whether they work with linux-firmware's fw or not. So for now this commit only restores the cs_config.bin and only updates pine64-pinephone and pine64-pinetab to pull it in.
Ref: #3179