net: dsa: sja1105: round up PTP perout pin duration

In the Linux kernel, the following vulnerability has been resolved: net: dsa: sja1105: round up PTP perout pin duration pin_duration is converted from the user-provided period to SJA1105 clock ticks and is later passed as the cycle_time argument to future_base_time(). Very small period values may become zero after the conversion, which can lead to a division by zero in future_base_time(). Round zero pin_duration up to 1 tick so that the smallest unsupported periods use the minimum non-zero hardware duration instead of passing zero to future_base_time().