configs: andes: add vender prefix for target name

Modify "CONFIG_TARGET_AE350" to "CONFIG_TARGET_ANDES_AE350"

Signed-off-by: Randolph <randolph@andestech.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/AndesTech/ae350/Kconfig b/board/AndesTech/ae350/Kconfig
index 75815bf..a85e7d6 100644
--- a/board/AndesTech/ae350/Kconfig
+++ b/board/AndesTech/ae350/Kconfig
@@ -1,4 +1,4 @@
-if TARGET_AE350
+if TARGET_ANDES_AE350
 
 config SYS_CPU
 	default "andesv5"