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/BSC9131RDB_NAND_SYSCLK100_defconfig b/configs/BSC9131RDB_NAND_SYSCLK100_defconfig
index e2c7cf3..3fd5b17 100644
--- a/configs/BSC9131RDB_NAND_SYSCLK100_defconfig
+++ b/configs/BSC9131RDB_NAND_SYSCLK100_defconfig
@@ -32,6 +32,7 @@
 CONFIG_MTDIDS_DEFAULT="nand0=ff800000.flash,"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=ff800000.flash:1m(uboot),8m(kernel),512k(dtb),-(fs)"
 CONFIG_ENV_IS_IN_NAND=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_FSL_CAAM=y
 # CONFIG_MMC is not set
 CONFIG_NAND=y