spi: kirkwood: Get drvdata in .ofdata_to_platdata

Get the is_errata_50mhz_ac in .ofdata_to_platdata, and
reuse it in .set_mode this can eventually initialized
dt code at once and adding room to add platdata.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c
index d6944af..4aa2c54 100644
--- a/drivers/spi/kirkwood_spi.c
+++ b/drivers/spi/kirkwood_spi.c
@@ -248,6 +248,7 @@
 
 struct mvebu_spi_platdata {
 	struct kwspi_registers *spireg;
+	bool is_errata_50mhz_ac;
 };
 
 struct mvebu_spi_priv {
@@ -309,7 +310,6 @@
 {
 	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
 	struct kwspi_registers *reg = plat->spireg;
-	const struct mvebu_spi_dev *drvdata;
 	u32 data = readl(&reg->cfg);
 
 	data &= ~(KWSPI_CPHA | KWSPI_CPOL | KWSPI_RXLSBF | KWSPI_TXLSBF);
@@ -323,8 +323,7 @@
 
 	writel(data, &reg->cfg);
 
-	drvdata = (struct mvebu_spi_dev *)dev_get_driver_data(bus);
-	if (drvdata->is_errata_50mhz_ac)
+	if (plat->is_errata_50mhz_ac)
 		mvebu_spi_50mhz_ac_timing_erratum(bus, mode);
 
 	return 0;
@@ -367,8 +366,11 @@
 static int mvebu_spi_ofdata_to_platdata(struct udevice *bus)
 {
 	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+	const struct mvebu_spi_dev *drvdata =
+		(struct mvebu_spi_dev *)dev_get_driver_data(bus);
 
 	plat->spireg = (struct kwspi_registers *)devfdt_get_addr(bus);
+	plat->is_errata_50mhz_ac = drvdata->is_errata_50mhz_ac;
 
 	return 0;
 }