xilinx: zynq: Add support for saving env based on bootmode

Enable saving variables to MMC(FAT), NAND, SPI based on primary
bootmode. If bootmode is JTAG, dont save env anywhere(NOWHERE).

Since most of the flashes on zynq evaluation boards are 16MB in size,
set default ENV_OFFSET to 15MB(0xE00000).

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/xilinx_zynq_virt_defconfig b/configs/xilinx_zynq_virt_defconfig
index 2fe5318..bdd6be2 100644
--- a/configs/xilinx_zynq_virt_defconfig
+++ b/configs/xilinx_zynq_virt_defconfig
@@ -4,6 +4,7 @@
 CONFIG_SYS_TEXT_BASE=0x4000000
 CONFIG_SYS_MEMTEST_START=0x00000000
 CONFIG_SYS_MEMTEST_END=0x00001000
+CONFIG_ENV_OFFSET=0xE00000
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x100000
 CONFIG_DM_GPIO=y
 CONFIG_SPL_STACK_R_ADDR=0x200000
@@ -55,7 +56,9 @@
 CONFIG_CMD_MTDPARTS_SHOW_NET_SIZES=y
 CONFIG_CMD_UBI=y
 CONFIG_OF_LIST="zynq-zc702 zynq-zc706 zynq-zc770-xm010 zynq-zc770-xm011 zynq-zc770-xm011-x16 zynq-zc770-xm012 zynq-zc770-xm013 zynq-cc108 zynq-microzed zynq-minized zynq-picozed zynq-zed zynq-zturn zynq-zturn-v5 zynq-zybo zynq-zybo-z7 zynq-dlc20-rev1.0"
-CONFIG_ENV_OVERWRITE=y
+CONFIG_ENV_IS_NOWHERE=y
+CONFIG_ENV_IS_IN_FAT=y
+CONFIG_ENV_IS_IN_NAND=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_NET_RANDOM_ETHADDR=y