arm: mvebu: helios4: mmc: move environment before 1M

Store the environment before 1M into the block device.
This constant is easier to remember, saves a little space,
and is in line with what SolidRun's 2018.01-based fork does for the
clearfog.
Signed-off-by: NJosua Mayer <josua.mayer97@gmail.com>
[ Aditya Prayoga:
* Port forward]
Signed-off-by: NAditya Prayoga <aditya@kobol.io>
Reviewed-by: NStefan Roese <sr@denx.de>
Tested-By: NDennis Gilmore <dgilmore@redhat.com>
Reviewed-By: NDennis Gilmore <dgilmore@redhat.com>
Signed-off-by: NStefan Roese <sr@denx.de>

include/configs/helios4.h

@@ -46,14 +46,9 @@
 /* Environment in MMC */
 #define CONFIG_SYS_MMC_ENV_DEV		0
 #define CONFIG_ENV_SECT_SIZE		0x200
-#define CONFIG_ENV_SIZE			0x10000
-/*
- * For SD - reserve 1 LBA for MBR + 1M for u-boot image. The MMC/eMMC
- * boot image starts @ LBA-0.
- * As result in MMC/eMMC case it will be a 1 sector gap between u-boot
- * image and environment
- */
-#define CONFIG_ENV_OFFSET		0xf0000
+#define CONFIG_ENV_SIZE			0x2000
+/* stay within first 1M */
+#define CONFIG_ENV_OFFSET		(SZ_1M - CONFIG_ENV_SIZE)
 #define CONFIG_ENV_ADDR			CONFIG_ENV_OFFSET
 
 #define CONFIG_PHY_MARVELL		/* there is a marvell phy */