spi: zynq: use to_platform_device()

Use to_platform_device() instead of open-coding it.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-zynqmp-gqspi.c

@@ -917,9 +917,7 @@ static int zynqmp_qspi_start_transfer(struct spi_master *master,
  */
 static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
 {
-	struct platform_device *pdev = container_of(dev,
-						    struct platform_device,
-						    dev);
+	struct platform_device *pdev = to_platform_device(dev);
 	struct spi_master *master = platform_get_drvdata(pdev);
 
 	spi_master_suspend(master);
@@ -940,9 +938,7 @@ static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
  */
 static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
 {
-	struct platform_device *pdev = container_of(dev,
-						    struct platform_device,
-						    dev);
+	struct platform_device *pdev = to_platform_device(dev);
 	struct spi_master *master = platform_get_drvdata(pdev);
 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
 	int ret = 0;