ath,ar9170: move CTL_ defines into regd.h

The ar9170 driver needs the defines for conformance test limit groups
and cannot include regd_common.h

Signed-off-by: Joerg Albert <jal2@gmx.de>
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>