Rename ap directory to 10.1

This will be the directory for all firmware images from
firmware branch 10.1.
main: add firmware-2.bin_999.999.0.636

This is the default from ath10k/QCA988X/hw2.0/firmware-2.bin.
Remove FW API 1 files

FW API 1 is nowadays unsupported, remove them altogether.
Disable execution bit for files
Make 10.1.467.2-1 as the default firmware