[netdrvr] removed unused #include <version.h>

The drivers below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/net/myri10ge/myri10ge.c
  drivers/net/netxen/netxen_nic_ethtool.c
  drivers/net/tokenring/lanstreamer.c

This patch removes the said #include <version.h>.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>