rtw89: regd: consider 6G band

Wrap regd debug dump into a macro and add dump for 6G band field.
Extend the macro used to configure regd table to account for multiple
bands beyond 2G and 5G.

And the follow-up commit will configure the corresponding values for
6G band into regd table.

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@kernel.org>
Link: https://lore.kernel.org/r/20220318023214.32411-4-pkshih@realtek.com