arm: mvebu: Add Armada A38x DB-88F6820-GP board support

This patch adds support for the Marvell DB-88F6820-GP Armada A38x
evaluation board.

Supported peripherals are:
- UART
- Ethernet (mvneta)
- I2C
- SPI (including SPI NOR flash)

Please note that this board support right now only supports the
main U-Boot. Without the bin_hdr integration (DDR training etc). This
will be added in a few days / weeks to complete this board port. But
till then this U-Boot version can be run on the target via the
original Marvell U-Boot via this command:

tftpboot 4000000 db-88f6820-gp/u-boot.bin;go 4000000

Signed-off-by: Stefan Roese <sr@denx.de>
Tested-by: Kevin Smith <kevin.smith@elecsyscorp.com>
Tested-by: Dirk Eibach <dirk.eibach@gdsys.cc>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 00be305..152a029 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -102,6 +102,11 @@
 	bool "Marvell Kirkwood"
 	select CPU_ARM926EJS
 
+config TARGET_DB_88F6820_GP
+	bool "Support DB-88F6820-GP"
+	select CPU_V7
+	select SUPPORT_SPL
+
 config TARGET_DB_MV784MP_GP
 	bool "Support db-mv784mp-gp"
 	select CPU_V7
@@ -850,6 +855,7 @@
 source "board/BuR/tseries/Kconfig"
 source "board/CarMediaLab/flea3/Kconfig"
 source "board/Marvell/aspenite/Kconfig"
+source "board/Marvell/db-88f6820-gp/Kconfig"
 source "board/Marvell/db-mv784mp-gp/Kconfig"
 source "board/Marvell/gplugd/Kconfig"
 source "board/altera/socfpga/Kconfig"