iwlwifi: mvm: dump Rx FIFO when the firmware asserts

The Rx FIFO includes valuable data - dump it when the FW
asserts. Also - free the SRAM and Rx FIFO when we create
the file, and don't collect new SRAM / Rx FIFO if the
previous file hasn't been collected through debugfs yet.

Also - add a comment to saying that the ASSERT output should
not be modified since we have automatic scripts that monitor
this output.

Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-prph.h

@@ -348,4 +348,12 @@ enum secure_load_status_reg {
 
 #define LMPM_SECURE_TIME_OUT	(100)
 
+/* Rx FIFO */
+#define RXF_SIZE_ADDR			(0xa00c88)
+#define RXF_SIZE_BYTE_CND_POS		(7)
+#define RXF_SIZE_BYTE_CNT_MSK		(0x3ff << RXF_SIZE_BYTE_CND_POS)
+
+#define RXF_LD_FENCE_OFFSET_ADDR	(0xa00c10)
+#define RXF_FIFO_RD_FENCE_ADDR		(0xa00c0c)
+
 #endif				/* __iwl_prph_h__ */