cfg80211: remove code about country IE support with OLD_REG

We had left in code to allow interested developers to add
support for parsing country IEs when OLD_REG was enabled.
This never happened and since we're going to remove OLD_REG
lets just remove these comments and code for it.

This code path was never being entered so this has no
functional change.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>