vexpress/armv8: Fix incorrect ethernet controller

This patch enables ethernet support in ARMv8 foundation model. The ARMv8
foundation model supports a SMSC91C111 integrated MAC and PHY module
which is present at base address 0x01A000000.

The previous implementation had enabled SMSC9115 ethernet controller
which is not present on the ARMv8 foundation model.

Tested on ARMv8 foundation model v1 and v2 by running ping/tftp
between the foundation model and the host PC via a bridged network.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@freescale.com>