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/am335x_evm_defconfig b/configs/am335x_evm_defconfig
index 599cbd6..151f71c 100644
--- a/configs/am335x_evm_defconfig
+++ b/configs/am335x_evm_defconfig
@@ -34,6 +34,7 @@
 CONFIG_OF_CONTROL=y
 CONFIG_DEFAULT_DEVICE_TREE="am335x-evm"
 CONFIG_OF_LIST="am335x-evm am335x-bone am335x-boneblack am335x-evmsk am335x-bonegreen am335x-icev2 am335x-pocketbeagle"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_SPL_ENV_IS_NOWHERE=y
 CONFIG_BOOTCOUNT_LIMIT=y