rtw88: declare hw supports ch 144

When driver was developed, FCC regulation didn't enable channel 144
and there was no demand for channel 144 at that time. Although HW
actually supports channel 144, driver didn't announce channel 144.
Therefore, channel 144 (20 MHz), channel 142 (40 MHz) and channel
138 (80 MHz) couldn't be used.

Today, channel 144 has been enabled by regulations and
is gradually being supported. With test requirements,
we declare hw supports channel 144.

Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201204013823.3729-1-pkshih@realtek.com