e1000e: Add pm_qos header

Commit e2c65448

 moved pm_qos_req to e1000_adapter. Add the header file
that defines the struct.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>