Revert "ath9k_hw: Updated AR9003 tx gain table for 5GHz"

commit 73b26df5fa1a6245d6fc982362518b620bc7c2fe upstream.

This reverts commit a240dc7b3c7463bd60cf0a9b2a90f52f78aae0fd.

This commit is reducing tx power by at least 10 db on some devices,
e.g. the Buffalo WZR-HP-G450H.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: rmanohar@qca.qualcomm.com
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>