mfd: db8500-prcmu: Check return of devm_ioremap for error

Error check around return value of devm_ioremap is missing. Add the same
to avoid NULL pointer dereference.
Signed-off-by: NPramod Gurav <pramod.gurav@smartplayin.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/db8500-prcmu.c

@@ -3167,6 +3167,11 @@ static int db8500_prcmu_probe(struct platform_device *pdev)
 	}
 	tcdm_base = devm_ioremap(&pdev->dev, res->start,
 			resource_size(res));
+	if (!tcdm_base) {
+		dev_err(&pdev->dev,
+			"failed to ioremap prcmu-tcdm register memory\n");
+		return -ENOENT;
+	}
 
 	/* Clean up the mailbox interrupts after pre-kernel code. */
 	writel(ALL_MBOX_BITS, PRCM_ARM_IT1_CLR);