ARM: at91: pm: add sama7g5 ddr controller

Add SAMA7G5 DDR controller to the list of DDR controller compatibles.
At the moment there is no standby support. Adapt the code for this.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20210415105010.569620-18-claudiu.beznea@microchip.com

arch/arm/mach-at91/pm.c

@@ -548,6 +548,7 @@ static const struct of_device_id ramc_ids[] __initconst = {
 	{ .compatible = "atmel,at91sam9260-sdramc", .data = &ramc_infos[1] },
 	{ .compatible = "atmel,at91sam9g45-ddramc", .data = &ramc_infos[2] },
 	{ .compatible = "atmel,sama5d3-ddramc", .data = &ramc_infos[3] },
+	{ .compatible = "microchip,sama7g5-uddrc", },
 	{ /*sentinel*/ }
 };
 
@@ -565,9 +566,11 @@ static __init void at91_dt_ramc(void)
 			panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
 
 		ramc = of_id->data;
-		if (!standby)
-			standby = ramc->idle;
-		soc_pm.data.memctrl = ramc->memctrl;
+		if (ramc) {
+			if (!standby)
+				standby = ramc->idle;
+			soc_pm.data.memctrl = ramc->memctrl;
+		}
 
 		idx++;
 	}