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/xilinx_zynqmp_r5_defconfig b/configs/xilinx_zynqmp_r5_defconfig
index de4460c..fa2960b 100644
--- a/configs/xilinx_zynqmp_r5_defconfig
+++ b/configs/xilinx_zynqmp_r5_defconfig
@@ -13,6 +13,7 @@
 CONFIG_CMD_BOOTSTAGE=y
 CONFIG_OF_EMBED=y
 CONFIG_DEFAULT_DEVICE_TREE="zynqmp-r5"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DEBUG_UART_ZYNQ=y
 CONFIG_ZYNQ_SERIAL=y
 CONFIG_TIMER=y