[Add fw_env.config for u-boot-fw-utils]

[Description]
Add fw_env.config for u-boot-fw-utils
1. add default fw_env.config for dual image

[Release-log]

diff --git a/recipes-bsp/u-boot/files/fw_env.config b/recipes-bsp/u-boot/files/fw_env.config
new file mode 100644
index 0000000..0887e7a
--- /dev/null
+++ b/recipes-bsp/u-boot/files/fw_env.config
@@ -0,0 +1 @@
+/dev/ubi0_0 0 0x80000 0x80000 1
\ No newline at end of file