Hello Vipin,
Can you please suggest a solution and let me know why CONFIG_USB is removed from my .config
The prefix for libpayload's configurations options changed to CONFIG_LP_, lately. The last commit for FILO (60d45fc) tried to fix it, but seems to have missed some options. So CONFIG_USB is CONFIG_LP_USB, now.
Also, if you get current FILO to compile with USB support, depending on your platform, it might not work as expected. I hit some strange regressions with older hardware this week, that I'm still investigating.
Nico