kvm_x86_64:  misc updates

Bundle together a few updates for the KVM target.

1 - disable CONFIG_MD in the kernel config.  For some reason CONFIG_MD
    does not play nice with the virtual machine's virtio block device.

2 - disable i2ctools and onie-syseeprom.  The VM does not have an
    EEPROM.

3 - use eth0's MAC address as is during boot up.