arm64: a37xx: add distro compatible env vars

the values of dt_addr_r/kernel_addr_r/ramdisk_addr_r are taken from
the downstream 'u-boot-2017.03-armada-17.10' release.

the chosen values of scriptaddr and pxefile_addr_r are below fdt_addr_r,
in 1MB steps.

Signed-off-by: Andre Heider <a.heider@gmail.com>
Reviewed-by: Konstantin Porotchkin <kostap@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>

include/configs/mvebu_armada-37xx.h

@@ -106,4 +106,11 @@
 
 #include <config_distro_defaults.h>
 
+#define CONFIG_EXTRA_ENV_SETTINGS	\
+	"scriptaddr=0x4d00000\0"	\
+	"pxefile_addr_r=0x4e00000\0"	\
+	"fdt_addr_r=0x4f00000\0"	\
+	"kernel_addr_r=0x5000000\0"	\
+	"ramdisk_addr_r=0x8000000"
+
 #endif /* _CONFIG_MVEBU_ARMADA_37XX_H */