spi: spi-zynqmp-gqspi: Fix call trace during QSPI suspend

During GQSPI diver probe a spi_controller instance is passed to
platform_set_drvdata( ) API. But in zynqmp_qspi_suspend( ) API the return
value of dev_get_drvdata(dev) is assigned to zynqmp_qspi instance instead
of spi_controller instance. This results in invalid pointer dereferencing
and causes kernel crash during QSPI suspend.
Fixed the issue by assigning the return value of dev_get_drvdata(dev) to
spi_controller instance in zynqmp_qspi_suspend API & then retrieving
zynqmp_qspi instance from spi_controller instance.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>

drivers/spi/spi-zynqmp-gqspi.c

@@ -1021,8 +1021,8 @@ static int zynqmp_qspi_read_op(struct zynqmp_qspi *xqspi, u8 rx_nbits,
  */
 static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
 {
-	struct zynqmp_qspi *xqspi = dev_get_drvdata(dev);
-	struct spi_controller *ctlr = xqspi->ctlr;
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);
 	int ret;
 
 	ret = spi_controller_suspend(ctlr);