Merge branch 'dpaa2-ptp-support-external-trigger-event'

Yangbo Lu says:

====================
dpaa2-ptp: support external trigger event

This patch-set is to add external trigger event support for
dpaa2-ptp driver since MC firmware has supported external
trigger interrupt with a new v2 dprtc_set_irq_mask() API.
And extts_clean_up() function in ptp_qoriq driver needs to be
exported with minor fixes for dpaa2-ptp reusing.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>