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/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index 79d8923..8f1ce40 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -61,6 +61,7 @@
 CONFIG_ENV_UBI_PART="UBI"
 CONFIG_ENV_UBI_VOLUME="uboot_config"
 CONFIG_ENV_UBI_VOLUME_REDUND="uboot_config_r"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_STM32_ADC=y
 CONFIG_USB_FUNCTION_FASTBOOT=y
 CONFIG_FASTBOOT_BUF_ADDR=0xC0000000