ath6kl: move diag commands to hif driver

This is preparation for USB support which will have different diag
commands.

Based on code by Kevin Fang.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/hif-ops.h

@@ -91,6 +91,26 @@ static inline int ath6kl_hif_suspend(struct ath6kl *ar,
 	return ar->hif_ops->suspend(ar, wow);
 }
 
+/*
+ * Read from the ATH6KL through its diagnostic window. No cooperation from
+ * the Target is required for this.
+ */
+static inline int ath6kl_hif_diag_read32(struct ath6kl *ar, u32 address,
+					 u32 *value)
+{
+	return ar->hif_ops->diag_read32(ar, address, value);
+}
+
+/*
+ * Write to the ATH6KL through its diagnostic window. No cooperation from
+ * the Target is required for this.
+ */
+static inline int ath6kl_hif_diag_write32(struct ath6kl *ar, u32 address,
+					  __le32 value)
+{
+	return ar->hif_ops->diag_write32(ar, address, value);
+}
+
 static inline int ath6kl_hif_bmi_read(struct ath6kl *ar, u8 *buf, u32 len)
 {
 	return ar->hif_ops->bmi_read(ar, buf, len);