e1000e: implement ethtool set_phys_id

e1000e: implement ethtool set_phys_id

Based on a patch from Stephen Hemminger <[email protected]>.

The new ethtool set_phys_id takes over controlling the LED for
identifying boards.  This fixes the lockout during that period.
For this device lots of extra infrastructure can also be removed by
using set_phys_id.

v2: - return blink frequency for parts that do not support blink in h/w
    - add blink_led function pointers for devices that do support blink
      in h/w to cleanup the test for this functionality

Signed-off-by: Bruce Allan <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Tested-by: Aaron Brown <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>