e1000e: fix acquisition of SW/FW/HW semaphore for ICHx parts

For ICHx parts, write the EXTCNF_CTRL.SWFLAG bit once when trying to
acquire the SW/FW/HW semaphore instead of multiple times to prevent the
hardware from having problems (especially for systems with manageability
enabled), and extend the timeout for the hardware to set the SWFLAG bit.

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>