sandbox: Implement fuzzing engine driver

Add a fuzzing engine driver for the sandbox to take inputs from
libfuzzer and expose them to the fuzz tests.

Signed-off-by: Andrew Scull <ascull@google.com>
diff --git a/drivers/fuzz/Makefile b/drivers/fuzz/Makefile
index acd8949..073743b 100644
--- a/drivers/fuzz/Makefile
+++ b/drivers/fuzz/Makefile
@@ -5,3 +5,4 @@
 #
 
 obj-$(CONFIG_DM_FUZZING_ENGINE) += fuzzing_engine-uclass.o
+obj-$(CONFIG_FUZZING_ENGINE_SANDBOX) += sandbox_fuzzing_engine.o