e1000e: enable CRC stripping by default

CRC stripping should be enabled by default but was not if it was not
specified as a module parameter.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>