wifi: rtw88: use RTW_FLAG_POWERON flag to prevent to power on/off twice

Use power state to decide whether we can enter or leave IPS accurately,
and then prevent to power on/off twice.

The commit 6bf3a083 ("wifi: rtw88: add flag check before enter or leave IPS")
would like to prevent this as well, but it still can't entirely handle all
cases. The exception is that WiFi gets connected and does suspend/resume,
it will power on twice and cause it failed to power on after resuming,
like:

  rtw_8723de 0000:03:00.0: failed to poll offset=0x6 mask=0x2 value=0x2
  rtw_8723de 0000:03:00.0: mac power on failed
  rtw_8723de 0000:03:00.0: failed to power on mac
  rtw_8723de 0000:03:00.0: leave idle state failed
  rtw_8723de 0000:03:00.0: failed to leave ips state
  rtw_8723de 0000:03:00.0: failed to leave idle state
  rtw_8723de 0000:03:00.0: failed to send h2c command

To fix this, introduce new flag RTW_FLAG_POWERON to reflect power state,
and call rtw_mac_pre_system_cfg() to configure registers properly between
power-off/-on.

Reported-by: Paul Gover <pmw.gover@yahoo.co.uk>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217016


Fixes: 6bf3a083 ("wifi: rtw88: add flag check before enter or leave IPS")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230216053633.20366-1-pkshih@realtek.com