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/am65x_evm_r5_defconfig b/configs/am65x_evm_r5_defconfig
index b82e9f6..17cf18a 100644
--- a/configs/am65x_evm_r5_defconfig
+++ b/configs/am65x_evm_r5_defconfig
@@ -52,6 +52,7 @@
 CONFIG_ENV_IS_IN_FAT=y
 CONFIG_ENV_FAT_INTERFACE="mmc"
 CONFIG_ENV_FAT_DEVICE_AND_PART="1:1"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM=y
 CONFIG_SPL_DM=y
 CONFIG_SPL_DM_SEQ_ALIAS=y