PWM drivers usually supports dead time generators that automatically
insert output activation delay for complementary PWM outputs. This
is usefull for some control purposes as control of H bridge for example.
This commit adds an application to driver interface that can be used
to set up those delays (if supported by the selected architecture)
directly from the application. The set up remains the same as for duty
cycle value.
The whole addition is by default disabled. It can be enabled by config
option PWM_DEADTIME.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>