bldcGimbal - Moved calcPowerScale from set_servo_us to set_speed_rpm
bldcGimbal - Moved calcPowerScale from set_servo_us to set_speed_rpm

This allows the power scaling to work even if we just use
set_speed directly.

rjehangir/tripolar,msperl/tripolar,msperl/tripolar,rjehangir/tripolar