net: keystone_net: add support for NETCP v1.5

Currently the network driver is used only by k2hk evm board.
The k2hk SoC contains NETCP v1.0, but Keystone2 SoCs, like k2e
contain NETCP v1.5. So driver should be able to work with such kind
of NETCP. This commit adds this opportunity. The main difference in
masks and some registers, the logic is the same, so only definitions
should be changed. To differentiate between versions add KS2_NETCP_V1_0
and KS2_NETCP_V1_5. Also remove unused and no more needed defines.

The port number is specific for each board so move this parameter to
configuration.

Acked-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Hao Zhang <hzhang@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>