Revert "ath: add support for special 0x0 regulatory domain"

Revert "ath: add support for special 0x0 regulatory domain"

This reverts commit 2dc016599cfa9672a147528ca26d70c3654a5423.

Users are reporting regressions in regulatory domain detection and
channel availability.

The problem this was trying to resolve was fixed in firmware anyway:

    QCA6174 hw3.0: sdio-4.4.1: add firmware.bin_WLAN.RMH.4.4.1-00042
    https://github.com/kvalo/ath10k-firmware/commit/4d382787f0efa77dba40394e0bc604f8eff82552

Link: https://bbs.archlinux.org/viewtopic.php?id=254535
Link: http://lists.infradead.org/pipermail/ath10k/2020-April/014871.html
Link: http://lists.infradead.org/pipermail/ath10k/2020-May/015152.html
Link: https://lore.kernel.org/all/1c160dfb-6ccc-b4d6-76f6-4364e0adb6dd@reox.at/
Fixes: 2dc016599cfa ("ath: add support for special 0x0 regulatory domain")
Cc: <stable@vger.kernel.org>
Cc: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20200527165718.129307-1-briannorris@chromium.org