arm64: a37xx: dts: Correct mpp definitions

This patch corrects below mpp definitions for armada 3720 DB board
and ESPRESSOBin board:
- "smi" pins group is added and "smi" function is set for eth0;
- Now pcie pins are used as gpio to implement PCIe function in
  hardware, so "pcie" group function is changed to "gpio".

Reviewed-on: http://vgitil04.il.marvell.com:8080/43287
Reviewed-by: Hua Jing <jinghua@marvell.com>
Tested-by: iSoC Platform CI <ykjenk@marvell.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Ken Ma <make@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/dts/armada-3720-db.dts b/arch/arm/dts/armada-3720-db.dts
index 88baf33..52fc134 100644
--- a/arch/arm/dts/armada-3720-db.dts
+++ b/arch/arm/dts/armada-3720-db.dts
@@ -82,7 +82,7 @@
 
 &eth0 {
 	pinctrl-names = "default";
-	pinctrl-0 = <&rgmii_pins>;
+	pinctrl-0 = <&rgmii_pins>, <&smi_pins>;
 	status = "okay";
 	phy-mode = "rgmii";
 };