configs: k2*_evm: let each board decide env location

Not all TI Keystone2 EVMs want environment in NAND flash.
K2G EVM which has an MMC/SD slot, keep environment in a
FAT partition on SD card.

Since ti_armv7_keystone2.h defines environment is in NAND,
boards which do not follow that have to #undef'ine that
configuration. This leads to ugly ordering issues around
where exactly the include of ti_armv7_keystone2.h can come
in within the k2*_evm.h files.

Move environment location to config file of each board.
This should make it easy to change it for any one board
without affecting all other boards.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
diff --git a/include/configs/k2e_evm.h b/include/configs/k2e_evm.h
index 3a7993e..b186bfc 100644
--- a/include/configs/k2e_evm.h
+++ b/include/configs/k2e_evm.h
@@ -27,6 +27,10 @@
 	"name_uboot=u-boot-spi-k2e-evm.gph\0"				\
 	"name_fs=arago-console-image-k2e-evm.cpio.gz\0"
 
+#define CONFIG_ENV_SIZE				(256 << 10)  /* 256 KiB */
+#define CONFIG_ENV_IS_IN_NAND
+#define CONFIG_ENV_OFFSET			0x100000
+
 #include <configs/ti_armv7_keystone2.h>
 
 /* SPL SPI Loader Configuration */