env: Add CONFIG_SYS_RELOC_GD_ENV_ADDR symbol

Today in initr_reloc_global_data() we use some non-obvious tests to
determine if we need to relocate the env_addr within gd or not.  In
order to facilitate migration of other symbols to Kconfig we need to
introduce a new symbol for this particular use case.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/Bananapi_M2_Ultra_defconfig b/configs/Bananapi_M2_Ultra_defconfig
index 40b6059..768d6e5 100644
--- a/configs/Bananapi_M2_Ultra_defconfig
+++ b/configs/Bananapi_M2_Ultra_defconfig
@@ -13,6 +13,7 @@
 CONFIG_SPL_I2C_SUPPORT=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_DEFAULT_DEVICE_TREE="sun8i-r40-bananapi-m2-ultra"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SCSI_AHCI=y
 CONFIG_RGMII=y
 CONFIG_SUN8I_EMAC=y