arm64: mvebu: Add Armada 3700 db-88f3720 development board support

This patch adds basic support for the Marvell Armada 3700 DB-88F3720
development board. Supported are the following interfaces:
- UART
- SPI (incl. SPI NOR)
- I2C
- Ethernet

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Wilson Ding <dingwei@marvell.com>
Cc: Victor Gu <xigu@marvell.com>
Cc: Hua Jing <jinghua@marvell.com>
Cc: Terry Zhou <bjzhou@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index f169fc5..58f2296 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -56,6 +56,10 @@
 	bool "Support ClearFog"
 	select 88F6820
 
+config TARGET_MVEBU_DB_88F3720
+	bool "Support DB-88F3720 Armada 3720"
+	select ARMADA_3700
+
 config TARGET_DB_88F6720
 	bool "Support DB-88F6720 Armada 375"
 	select ARMADA_375
@@ -88,6 +92,7 @@
 
 config SYS_BOARD
 	default "clearfog" if TARGET_CLEARFOG
+	default "mvebu_db-88f3720" if TARGET_MVEBU_DB_88F3720
 	default "db-88f6720" if TARGET_DB_88F6720
 	default "db-88f6820-gp" if TARGET_DB_88F6820_GP
 	default "db-88f6820-amc" if TARGET_DB_88F6820_AMC
@@ -98,6 +103,7 @@
 
 config SYS_CONFIG_NAME
 	default "clearfog" if TARGET_CLEARFOG
+	default "mvebu_db-88f3720" if TARGET_MVEBU_DB_88F3720
 	default "db-88f6720" if TARGET_DB_88F6720
 	default "db-88f6820-gp" if TARGET_DB_88F6820_GP
 	default "db-88f6820-amc" if TARGET_DB_88F6820_AMC
@@ -108,6 +114,7 @@
 
 config SYS_VENDOR
 	default "Marvell" if TARGET_DB_MV784MP_GP
+	default "Marvell" if TARGET_MVEBU_DB_88F3720
 	default "Marvell" if TARGET_DB_88F6720
 	default "Marvell" if TARGET_DB_88F6820_GP
 	default "Marvell" if TARGET_DB_88F6820_AMC