IBM-EMAC: constify of_device_id array

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/ethernet/ibm/emac/core.c
Simple merge

diff --cc drivers/net/ethernet/ibm/emac/mal.c
Simple merge

diff --cc drivers/net/ethernet/ibm/emac/rgmii.c
Simple merge

diff --cc drivers/net/ethernet/ibm/emac/tah.c
Simple merge

diff --cc drivers/net/ethernet/ibm/emac/zmii.c
Simple merge