staging: wlan-ng: Replace hard coded values with MACRO's

This patch replaces hard coded values with global definitions for the
Ethernet IEEE 802.3 interface defined in standard header file.

Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>