e1000: updated whitespace and comments

A large whitespace change to e1000_hw.[ch] in order to update it to kernel coding
style (by running lindent).  Updated function header comments into kdoc style.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>