rtw88: 8822c: remove CCK TX setting when switch channel

The CCK TX setting when switch channel will fix the CCK to
path A only, so if the antenna is configured to path B
(e.g. iw phy set antenna 0x2 0x3 "TX B/RX AB"), then the CCK
packets can never be delivered to the air if only path B is
connected with an antenna (it can possibly be transmitted
through path A, but as path B is configured, the expected
behavior is incorrect).

This can also solve the racing issue of CCK TX setting between
driver and firmware. The CCK TX setting in driver should be
removed. Otherwise, the CCK TX setting would be wrong when the
racing occurs.

Fixes: 297bcf82 ("rtw88: add support for set/get antennas")
Signed-off-by: Chien-Hsun Liao <ben.liao@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200522091234.24495-1-yhchuang@realtek.com