wireless-regdb: Add Chad (TD) regulatory rules

Source is QCA's regulatory team's efforts and correspondence with
regulator: http://otrt.td [L'Office Tchadien de Régulation des
Télécommunications (OTRT)].

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>