clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource

Use devm_platform_ioremap_resource() to simplify code, which
wraps 'platform_get_resource' and 'devm_ioremap_resource' in a
single helper.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191221173027.30716-2-tiny.windzz@gmail.com

drivers/clocksource/em_sti.c

@@ -279,7 +279,6 @@ static void em_sti_register_clockevent(struct em_sti_priv *p)
 static int em_sti_probe(struct platform_device *pdev)
 {
 	struct em_sti_priv *p;
-	struct resource *res;
 	int irq;
 	int ret;
 
@@ -295,8 +294,7 @@ static int em_sti_probe(struct platform_device *pdev)
 		return irq;
 
 	/* map memory, let base point to the STI instance */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	p->base = devm_ioremap_resource(&pdev->dev, res);
+	p->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(p->base))
 		return PTR_ERR(p->base);