Added a feature to choose the controlled switch.
* The duty cycle will be applied according to the convention chosen in initialization with upper_switch_convention. In hrtim_cmpl_pwm_out() if it is set to "true" then the duty cycle will be applied on the upper switch and the lower switch will complement the PWM and vice versa for "false". * The dead time of the PWMs is now transferred to the complementary switch of the switching cell. As the dead time is by default centered on the two signals of the switch cell, it has been compensated on the main switch to be controlled at the duty cycle requested in leg_set() * A correction has been made on the PWMs specific to the actual power board. The signals of the first switching cell are inverted, so this has been corrected in the initialization of HRTIM in hrtim_cmpl_pwm_out()