Staging: hv: make the Hyper-V virtual network driver build

The #define KERNEL_2_6_27 needs to be set, and I adjusted the include
directories a bit to get things to build properly.

The driver was changed to use net_device_ops, as that is needed to build
and operate properly now.

The hv_netvsc code should now build with no errors.

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>