wifi: rtw89: 8922a: add coexistence helpers of SW grant

Under some circumstances, coexistence mechanism want to keep grant BT or
WiFi, such as inquiry and WiFi is connecting, to ensure BT or WiFi can
transmit or receive data in that period.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240229074514.219276-3-pkshih@realtek.com