iwlwifi: fix Bz NMI behaviour

Contrary to what was stated before, the hardware hasn't changed
the bits here yet. In any case, the new CSR is also directly
(lower 16 bits) connected to UREG_DOORBELL_TO_ISR6, so if it
still changes the changes would be there. Adjust the code and
comments accordingly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 6c0795f1 ("iwlwifi: implement Bz NMI behaviour")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211210090244.75b6207536e3.I7d170a48a9096e6b7269c3a9f447c326f929b171@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-csr.h

@@ -109,9 +109,10 @@
 #define CSR_IPC_SLEEP_CONTROL_SUSPEND	0x3
 #define CSR_IPC_SLEEP_CONTROL_RESUME	0
 
-/* Doorbell NMI (since Bz) */
+/* Doorbell - since Bz
+ * connected to UREG_DOORBELL_TO_ISR6 (lower 16 bits only)
+ */
 #define CSR_DOORBELL_VECTOR	(CSR_BASE + 0x130)
-#define CSR_DOORBELL_VECTOR_NMI	BIT(1)
 
 /* host chicken bits */
 #define CSR_HOST_CHICKEN	(CSR_BASE + 0x204)

drivers/net/wireless/intel/iwlwifi/iwl-io.c

@@ -218,7 +218,7 @@ void iwl_force_nmi(struct iwl_trans *trans)
 				    UREG_DOORBELL_TO_ISR6_NMI_BIT);
 	else
 		iwl_write32(trans, CSR_DOORBELL_VECTOR,
-			    CSR_DOORBELL_VECTOR_NMI);
+			    UREG_DOORBELL_TO_ISR6_NMI_BIT);
 }
 IWL_EXPORT_SYMBOL(iwl_force_nmi);