fsl/fman: Workaround for Errata A-007273

Errata A-007273 (For FMan V3 devices only):
FMan soft reset is not finished properly if one
of the Ethernet MAC clocks is disabled

Workaround:
Re-enable all disabled MAC clocks through the DCFG_CCSR_DEVDISR2
register prior to issuing an FMAN soft reset.
Re-disable the MAC clocks after the FMAN soft reset is done.

Signed-off-by: Igal Liberman <igal.liberman@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>