spi: cadence-qspi: Move ref clock calculation to probe

"assigned-clock-parents" and "assigned-clock-rates" DT properties take
effect only after ofdata_to_platdata() when clk_set_defaults() is called
in device_probe(). Therefore clk get rate() would return a wrong value
in ofdata_to_platdata() when compared with probe. Hence it needs to be
moved to probe.

Tested on u-boot-ti/next.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
index 83b114f..994a594 100644
--- a/drivers/spi/cadence_qspi.c
+++ b/drivers/spi/cadence_qspi.c
@@ -166,11 +166,28 @@
 {
 	struct cadence_spi_platdata *plat = bus->platdata;
 	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	struct clk clk;
 	int ret;
 
 	priv->regbase = plat->regbase;
 	priv->ahbbase = plat->ahbbase;
 
+	if (plat->ref_clk_hz == 0) {
+		ret = clk_get_by_index(bus, 0, &clk);
+		if (ret) {
+#ifdef CONFIG_CQSPI_REF_CLK
+			plat->ref_clk_hz = CONFIG_CQSPI_REF_CLK;
+#else
+			return ret;
+#endif
+		} else {
+			plat->ref_clk_hz = clk_get_rate(&clk);
+			clk_free(&clk);
+			if (IS_ERR_VALUE(plat->ref_clk_hz))
+				return plat->ref_clk_hz;
+		}
+	}
+
 	ret = reset_get_bulk(bus, &priv->resets);
 	if (ret)
 		dev_warn(bus, "Can't get reset: %d\n", ret);
@@ -268,8 +285,6 @@
 {
 	struct cadence_spi_platdata *plat = bus->platdata;
 	ofnode subnode;
-	struct clk clk;
-	int ret;
 
 	plat->regbase = (void *)devfdt_get_addr_index(bus, 0);
 	plat->ahbbase = (void *)devfdt_get_addr_size_index(bus, 1,
@@ -305,20 +320,6 @@
 	plat->tchsh_ns = ofnode_read_u32_default(subnode, "cdns,tchsh-ns", 20);
 	plat->tslch_ns = ofnode_read_u32_default(subnode, "cdns,tslch-ns", 20);
 
-	ret = clk_get_by_index(bus, 0, &clk);
-	if (ret) {
-#ifdef CONFIG_CQSPI_REF_CLK
-		plat->ref_clk_hz = CONFIG_CQSPI_REF_CLK;
-#else
-		return ret;
-#endif
-	} else {
-		plat->ref_clk_hz = clk_get_rate(&clk);
-		clk_free(&clk);
-		if (IS_ERR_VALUE(plat->ref_clk_hz))
-			return plat->ref_clk_hz;
-	}
-
 	debug("%s: regbase=%p ahbbase=%p max-frequency=%d page-size=%d\n",
 	      __func__, plat->regbase, plat->ahbbase, plat->max_hz,
 	      plat->page_size);