sandbox: Add a new 'sb' command

The old 'sb' command was deprecated in 2015 and replaced with 'host'. It
is useful to be able to access some internal sandbox state, particularly
for testing.

Resurrect the old command and provide a way to print some basic state
information (currently just the arguments to sandbox).

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h
index 0a2e3c4..8fabe70 100644
--- a/arch/sandbox/include/asm/state.h
+++ b/arch/sandbox/include/asm/state.h
@@ -243,6 +243,13 @@
 void state_reset_for_test(struct sandbox_state *state);
 
 /**
+ * state_show() - Show information about the sandbox state
+ *
+ * @param state		Sandbox state to show
+ */
+void state_show(struct sandbox_state *state);
+
+/**
  * Initialize the test system state
  */
 int state_init(void);