net: netcp: Fixes efuse mac addr swap on k2e and k2l

On some of the K2E and K2L platforms, the two DWORDs in
efuse occupied by the pre-programmed mac address for
slave port 1 are swapped.  To workaround this issue,
this patch adds a new define NETCP_EFUSE_ADDR_SWAP (2)
which signifies the occurrence of such swapping so that
the driver can take proper action.  The flag can be
enabled in the corresponding netcp interface dts binding
as efuse-mac = <2>  under the corresponding netcp
interface node.

Signed-off-by: WingMan Kwok <w-kwok2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>