iwlwifi: mvm: Add debugfs entry to generate NMI to NIC

Writting to fw_nmi entry will set DEVICE_SET_NMI_REG (0x00a01c30)
generating NMI that halts NIC CPU.

Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-prph.h b/drivers/net/wireless/iwlwifi/iwl-prph.h
index a70c7b9..f6412da 100644
--- a/drivers/net/wireless/iwlwifi/iwl-prph.h
+++ b/drivers/net/wireless/iwlwifi/iwl-prph.h
@@ -102,6 +102,9 @@
 /* Device system time */
 #define DEVICE_SYSTEM_TIME_REG 0xA0206C
 
+/* Device NMI register */
+#define DEVICE_SET_NMI_REG 0x00a01c30
+
 /*****************************************************************************
  *                        7000/3000 series SHR DTS addresses                 *
  *****************************************************************************/