Increase arbitrary MAX_AXIS limit

[kmpeters]

MAX_AXIS was last increased (from 10 to 32) twenty years ago:

https://github.com/epics-modules/motor/commit/141daff8174a2dbac1ab7162b8c5ca258fcd0c3a

Controllers that support 64 axes are increasingly common. MAX_AXIS should probably be increase to 128.

MAX_AXIS only appears to be used in one location:

https://github.com/epics-modules/motor/blob/81662468d0ab2ff0896eb6fbfab214165122ceb2/motorApp/MotorSrc/motordrvCom.h#L178

[MarkRivers]

And the one place it is used is only for Model 1 drivers which should never be used for new drivers.

[kmpeters]

@MarkRivers, are you aware of any 32-axis limitations for model-3 drivers? I didn't find any in the asyn motor support or my brief search of the asyn module.

Axilion has reported a 32-axis limitation with motorAcsMotion, but the driver-imposed maximun number of axes has been 64 for the last four years.

[MarkRivers]

I don’t know of any, but I have searched.