Create a single cmd_call() function to handle command execution

We should aim for a single point of entry to the commands, whichever
parser is used.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/command.h b/include/command.h
index 3912b80..6dc694f 100644
--- a/include/command.h
+++ b/include/command.h
@@ -112,6 +112,8 @@
 #endif
 extern int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
 
+int cmd_call(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
 #endif	/* __ASSEMBLY__ */
 
 /*
@@ -150,4 +152,5 @@
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 void fixup_cmdtable(cmd_tbl_t *cmdtp, int size);
 #endif
+
 #endif	/* __COMMAND_H */