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/sheep-rk3368_defconfig b/configs/sheep-rk3368_defconfig
index 4883f59..7ec0fb0 100644
--- a/configs/sheep-rk3368_defconfig
+++ b/configs/sheep-rk3368_defconfig
@@ -13,6 +13,7 @@
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_CMD_MMC=y
 CONFIG_DEFAULT_DEVICE_TREE="rk3368-sheep"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_REGMAP=y
 CONFIG_SYSCON=y
 CONFIG_CLK=y