Added special UART4 init to sample if FlySky sticks are present or not.
Added boolean globalData.flyskygimbals to save the detection result.
Removed FLYSKY_HALL_STICKS and FLYSKY_HALL_STICKS_REVERSE CMake build options.
Tested on two RM TX16S radios, one with FlySky digital hall sticks and second with stock analog sticks.