ath10k: don't enable interrupts for the diagnostic window

The diagnostic window (CE7) uses polling and is not initiliased to retrieve
interrupts so disable interrupts altogether for CE7. Otherwise ath10k crashes
when using the diagnostic window while the firmware is running due to NULL
dereference and polling reads timeout.
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/ce.c

@@ -817,7 +817,10 @@ void ath10k_ce_enable_interrupts(struct ath10k *ar)
 	struct ath10k_pci *ar_pci = ath10k_pci_priv(ar);
 	int ce_id;
 
-	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
+	/* Skip the last copy engine, CE7 the diagnostic window, as that
+	 * uses polling and isn't initialized for interrupts.
+	 */
+	for (ce_id = 0; ce_id < CE_COUNT - 1; ce_id++)
 		ath10k_ce_per_engine_handler_adjust(&ar_pci->ce_states[ce_id]);
 }