gpio: dw: Add ngpios DT-property support

Starting with Linux commit 7569486d79ae ("gpio: dwapb: Add ngpios
DT-property support") the "snps,nr-gpios" property was marked
as deprecated.

And since all newly added dw-apb-gpio nodes are described using generic
"ngpios" property, it's time to add support for it.

Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/drivers/gpio/dwapb_gpio.c b/drivers/gpio/dwapb_gpio.c
index 7a6eae9..04639a4 100644
--- a/drivers/gpio/dwapb_gpio.c
+++ b/drivers/gpio/dwapb_gpio.c
@@ -177,7 +177,9 @@
 
 		plat->base = (void *)base;
 		plat->bank = bank;
-		plat->pins = ofnode_read_u32_default(node, "snps,nr-gpios", 0);
+
+		if (ofnode_read_u32(node, "ngpios", &plat->pins))
+			plat->pins = ofnode_read_u32_default(node, "snps,nr-gpios", 0);
 
 		if (ofnode_read_string_index(node, "bank-name", 0,
 					     &plat->name)) {