rtlwifi: btcoexist: Implement antenna selection

commit baa17022 upstream.

The previous patch added an option to rtl8723be to manually select the
antenna for those cases when only a single antenna is present, and the
on-board EEPROM is incorrectly programmed. This patch implements the
necessary changes in the Bluetooth coexistence driver.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>