hekate: clean unused stuff

Remove anything that will never be in TUI in the future.
Especially these that need modernization.

bootloader/frontend/fe_info.h

@@ -23,7 +23,6 @@ void print_fuseinfo();
 void print_kfuseinfo();
 void print_mmc_info();
 void print_sdcard_info();
-void print_tsec_key();
 void print_fuel_gauge_info();
 void print_battery_charger_info();
 void print_battery_info();