RC Servo always disabled when Stepper/EnableInvert is ON

[gautamjain]

Firmware Version: 1.3a Date 20210816

Repeatable? Yes

Conditions:

• $Stepper/EnableInvert=On (e.g. for use with TMC5160 SilentStepStick drivers)
• Using an RC servo
• Custom hardware controller (but I believe this is not causing the issue)

Bug: RC servo is always disabled (there is no PWM signal generated). I think this is happening because Stepper/EnableInvert is a global flag and is being applied to all motors/axis. If using Trinamic drivers, the enable inversion works as expected. But if you also have an RC servo, then the inversion causes it to get disabled - which should not happen.

https://github.com/bdring/Grbl_Esp32/blob/5316c64abb4d2de994799c09621c777391cd2386/Grbl_Esp32/src/Motors/Motors.cpp#L425-L437

[bdring]

I'll look at that when I get a chance.