configs: keystone2: Change to using env files

Move to using .env file for setting up environment variables for K2x_evm.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/ti/ks2_evm/Kconfig b/board/ti/ks2_evm/Kconfig
index 9477f53..8b3a43a 100644
--- a/board/ti/ks2_evm/Kconfig
+++ b/board/ti/ks2_evm/Kconfig
@@ -9,6 +9,9 @@
 config SYS_CONFIG_NAME
 	default "k2e_evm"
 
+config ENV_SOURCE_FILE
+       default "k2e_evm"
+
 endif
 
 if TARGET_K2HK_EVM
@@ -22,6 +25,9 @@
 config SYS_CONFIG_NAME
 	default "k2hk_evm"
 
+config ENV_SOURCE_FILE
+       default "k2hk_evm"
+
 endif
 
 if TARGET_K2L_EVM
@@ -35,6 +41,9 @@
 config SYS_CONFIG_NAME
 	default "k2l_evm"
 
+config ENV_SOURCE_FILE
+       default "k2l_evm"
+
 endif
 
 if TARGET_K2G_EVM
@@ -48,6 +57,9 @@
 config SYS_CONFIG_NAME
 	default "k2g_evm"
 
+config ENV_SOURCE_FILE
+       default "k2g_evm"
+
 endif
 
 source "board/ti/common/Kconfig"