Enable XZ-compressed firmware support

configname: CONFIG_FW_LOADER_COMPRESS_XZ

Linux Kernel Configuration
└─>Device Drivers
└─>Generic Driver Options
└─>Firmware loader
└─>Enable XZ-compressed firmware support
In linux kernel since version 5.2 (release Date: 2019-07-07)  
This option adds the support for XZ-compressed files.
The files have to be compressed with either none or crc32
integrity check type (pass "-C crc32" option to xz command).