rtlwifi: rtl8821ae: Fix 5G failure when EEPROM is incorrectly encoded

rtlwifi: rtl8821ae: Fix 5G failure when EEPROM is incorrectly encoded

Recently, it has been reported that D-Link DWA-582 cards, which use an
RTL8812AE chip are not able to scan for 5G networks. The problems started
with kernel 4.2, which is the first version that had commit 0533df715ce7
("rtlwifi: rtl8821ae: Fix problem with regulatory information"). With this
patch, the driver went from setting a default channel plan to using
the value derived from EEPROM.

Bug reports at https://bugzilla.kernel.org/show_bug.cgi?id=111031 and
https://bugzilla.redhat.com/show_bug.cgi?id=1279653 are examples of this
problem.

The problem was solved once I learned that the internal country code was
resulting in a regulatory set with only 2.4 GHz channels. With the RTL8821AE
chips available to me, the country code was such that both 2.4 and 5 GHz
channels are allowed. The fix is to allow both bands even when the EEPROM
is incorrectly encoded.

Fixes: 0533df715ce7 ("rtlwifi: rtl8821ae: Fix problem with regulatory information")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: littlesmartguy@gmail.com
Cc: gabe@codehaus.org
Cc: Stable <stable@vger.kernel.org> [v4.2+]
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>