ath5k: Update interrupt masking code

*Properly get/set all available ISR/IMR values and review common/uncommon bits
*Better handling of per-txq interrupts (we can now resolve what q is generating
 each interrupt -this will help in debuging wme later)
*Some minor updates from legacy-hal
*Properly handle RXNOFRM and TXNOFRM interrupt masking (even when we don't set
 them on IMR they keep showing up, so we disable them by zeroing AR5K_RXNOFRM
 and AR5K_TXNOFRM registers). This doesn't exist on legacy-hal but i've tested
 it on various cards and it works fine.

Changes-Licensed-under: ISC
Signed-Off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath5k/reset.c b/drivers/net/wireless/ath5k/reset.c
index 1b6d45b..b51bc03 100644
--- a/drivers/net/wireless/ath5k/reset.c
+++ b/drivers/net/wireless/ath5k/reset.c
@@ -864,8 +864,7 @@
 
 	/* Pre-enable interrupts on 5211/5212*/
 	if (ah->ah_version != AR5K_AR5210)
-		ath5k_hw_set_imr(ah, AR5K_INT_RX | AR5K_INT_TX |
-				AR5K_INT_FATAL);
+		ath5k_hw_set_imr(ah, ah->ah_imr);
 
 	/*
 	 * Set RF kill flags if supported by the device (read from the EEPROM)