hwrng: stm32 - Fix build with CONFIG_PM

Commit c6a97c42e399 ("hwrng: stm32 - add support for STM32 HW RNG")
was inadequately tested (actually it was tested quite hard so
incompetent would be a better description that inadequate) and does
not compile on platforms with CONFIG_PM set.

Fix this.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/stm32-rng.c

@@ -160,7 +160,7 @@ static int stm32_rng_probe(struct platform_device *ofdev)
 #ifdef CONFIG_PM
 static int stm32_rng_runtime_suspend(struct device *dev)
 {
-	struct stm32_rng_private *priv = dev_get_drvdata(pdev);
+	struct stm32_rng_private *priv = dev_get_drvdata(dev);
 
 	stm32_rng_cleanup(&priv->rng);
 
@@ -169,7 +169,7 @@ static int stm32_rng_runtime_suspend(struct device *dev)
 
 static int stm32_rng_runtime_resume(struct device *dev)
 {
-	struct stm32_rng_private *priv = dev_get_drvdata(pdev);
+	struct stm32_rng_private *priv = dev_get_drvdata(dev);
 
 	return stm32_rng_init(&priv->rng);
 }