b43: Add myself to module authors & to LP-PHY file copyright notices

Also mark the LP-PHY driver "802.11a/g" instead of "802.11g",
as LP-PHY is capable of both 2GHz and 5GHz operation.

Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>