ARM: at91: pm: fix SRAM allocation

On some platforms, there are multiple SRAM nodes defined in the device tree but
some of them are disabled, leading to allocation failure. Try to find the first
enabled SRAM node and allocate from it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/mach-at91/pm.c

@@ -270,37 +270,35 @@ static void __init at91_pm_sram_init(void)
 	phys_addr_t sram_pbase;
 	unsigned long sram_base;
 	struct device_node *node;
-	struct platform_device *pdev;
+	struct platform_device *pdev = NULL;
 
-	node = of_find_compatible_node(NULL, NULL, "mmio-sram");
-	if (!node) {
-		pr_warn("%s: failed to find sram node!\n", __func__);
-		return;
+	for_each_compatible_node(node, NULL, "mmio-sram") {
+		pdev = of_find_device_by_node(node);
+		if (pdev) {
+			of_node_put(node);
+			break;
+		}
 	}
 
-	pdev = of_find_device_by_node(node);
 	if (!pdev) {
 		pr_warn("%s: failed to find sram device!\n", __func__);
-		goto put_node;
+		return;
 	}
 
 	sram_pool = dev_get_gen_pool(&pdev->dev);
 	if (!sram_pool) {
 		pr_warn("%s: sram pool unavailable!\n", __func__);
-		goto put_node;
+		return;
 	}
 
 	sram_base = gen_pool_alloc(sram_pool, at91_slow_clock_sz);
 	if (!sram_base) {
 		pr_warn("%s: unable to alloc ocram!\n", __func__);
-		goto put_node;
+		return;
 	}
 
 	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
 	slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz, false);
-
-put_node:
-	of_node_put(node);
 }
 #endif