e1000e: use msleep instead of mdelay

The e1000_link_stall_workaround_lv() function is always called in non-
atomic context so it should use msleep instead of mdelay.  Also, remove
unnecessary #include <linux/delay.h>.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>