Revert #12311 PIO LDF work-around (#12484)

platformio.ini

 board         = at90usb1286
 build_flags   = ${common.build_flags}
 lib_deps      = ${common.lib_deps}
-lib_ignore    = Teensy_ADC
 lib_ldf_mode  = deep+
 src_filter    = ${common.default_src_filter} +<src/HAL/HAL_AVR>
 extra_scripts = pre:buildroot/share/atom/create_custom_upload_command_CDC.py
 board         = at90usb1286
 build_flags   = ${common.build_flags}
 lib_deps      = ${common.lib_deps}
-lib_ignore    = Teensy_ADC
 lib_ldf_mode  = deep+
 src_filter    = ${common.default_src_filter} +<src/HAL/HAL_AVR>
 extra_scripts = pre:buildroot/share/atom/create_custom_upload_command_DFU.py