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/mx28evk_spi_defconfig b/configs/mx28evk_spi_defconfig
index 6e06571..5d64408 100644
--- a/configs/mx28evk_spi_defconfig
+++ b/configs/mx28evk_spi_defconfig
@@ -36,6 +36,7 @@
 CONFIG_MTDIDS_DEFAULT="nand0=gpmi-nand"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=gpmi-nand:3m(bootloader)ro,512k(environment),512k(redundant-environment),4m(kernel),512k(fdt),8m(ramdisk),-(filesystem)"
 CONFIG_CMD_UBI=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_MXS_GPIO=y
 CONFIG_MMC_MXS=y
 CONFIG_NAND=y