IXXAT send_periodic not works with interface that does not include FEATURE_SCHEDULER

[prunith]

Describe the bug Some of IXXAT board does not include FEATURE_SCHEDULER and as IXXAT internal scheduler is used by default in python CAN it return error "Division by Zero" when send_peridic_message is used.

To Reproduce Try to use send_peridic_message with IXXAT PCI_Can card.

Expected behavior _send_periodic_internal should check caps.dwFeatures if FEATURE_SCHEDULER is available on the hardware if not fall down to to generic send_periodic feature (thead)

    def _send_periodic_internal(self, msg, period, duration=None):
        """Send a message using built-in cyclic transmit list functionality."""
        if self._scheduler is None:
            self._scheduler = HANDLE()
            _canlib.canSchedulerOpen(self._device_handle, self.channel,
                                     self._scheduler)
            caps = structures.CANCAPABILITIES()
            _canlib.canSchedulerGetCaps(self._scheduler, caps)
            self._scheduler_resolution = float(caps.dwClockFreq) / caps.dwCmsDivisor
            _canlib.canSchedulerActivate(self._scheduler, constants.TRUE)
        return CyclicSendTask(self._scheduler, msg, period, duration,
                              self._scheduler_resolution)

also Doc of VCI API :

dwCmsDivisor:[out] Divisor factor for the timer of the cyclic transmit list. The frequency of the timer is calculated from the frequency of the primary timer divided by the value specified here. If no cyclic transmit list is available, the field has the value 0.

dwCmsDivisor = 0 when schedule feature is not available

[felixdivo]

I don't have an IXXAT device on hand, but pull requests are always welcome!