TI DaVinci EMAC: Convert to dev_pm_ops

Migrate from the legacy PM hooks to use dev_pm_ops structure.

Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: David S. Miller <davem@davemloft.net>