build: add option to delete intermediate files

Add option to remove intermediate files to save space and remove
clutter.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/Kconfig.zephyr b/Kconfig.zephyr
index 698e642..e4b96a5 100644
--- a/Kconfig.zephyr
+++ b/Kconfig.zephyr
@@ -295,6 +295,12 @@
 	  ram_report and
 	  https://sourceware.org/binutils/docs/ld/MEMORY.html
 
+config CLEANUP_INTERMEDIATE_FILES
+	bool "Remove all intermediate files"
+	help
+	  Delete intermediate files to save space and cleanup clutter resulting
+	  from the build process.
+
 config BUILD_NO_GAP_FILL
 	bool "Don't fill gaps in generated hex/bin/s19 files."