ath9k: improve suspend/resume reliability

Ensure that drv_start() always returns true, as a failing hw start usually
eventually leads to crashes when there's still a station entry present.
Call a power-on reset after a resume and after a hw reset failure to bring
the hardware back to life again.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index f9a6ec5..8e1559a 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1450,9 +1450,14 @@
 	REG_WRITE(ah, AR_RTC_FORCE_WAKE,
 		  AR_RTC_FORCE_WAKE_EN | AR_RTC_FORCE_WAKE_ON_INT);
 
+	if (!ah->reset_power_on)
+		type = ATH9K_RESET_POWER_ON;
+
 	switch (type) {
 	case ATH9K_RESET_POWER_ON:
 		ret = ath9k_hw_set_reset_power_on(ah);
+		if (!ret)
+			ah->reset_power_on = true;
 		break;
 	case ATH9K_RESET_WARM:
 	case ATH9K_RESET_COLD: