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/M5275EVB_defconfig b/configs/M5275EVB_defconfig
index ecb3e32..246b1b0 100644
--- a/configs/M5275EVB_defconfig
+++ b/configs/M5275EVB_defconfig
@@ -16,6 +16,7 @@
 CONFIG_CMD_PING=y
 CONFIG_CMD_CACHE=y
 CONFIG_DEFAULT_DEVICE_TREE="M5275EVB"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_FLASH_CFI_DRIVER=y
 CONFIG_SYS_FLASH_CFI=y