net/wireless: ipw2x00: remove unused definitions for regulatory domain

ipw2200 driver does not use these defines, it uses geo struct instead.
Therefore remove them from its header.

Note: we keep them in the ipw2100 driver's header, because the driver
still uses them.

Signed-off-by: Stanislav Yakovlev <stas.yakovlev@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>