dpaa2-ptp: reuse ptp_qoriq driver

Although dpaa2-ptp.c driver is a fsl_mc_driver which
is using MC APIs for register accessing, it's same IP
block with eTSEC/DPAA/ENETC 1588 timer.
This patch is to convert to reuse ptp_qoriq driver by
using register ioremap and dropping related MC APIs.
However the interrupts could only be handled by MC which
fires MSIs to ARM cores. So the interrupt enabling and
handling still rely on MC APIs.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>