Command usage cleanup

Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>

common/cmd_bdinfo.c

@@ -444,6 +444,6 @@ static void print_str(const char *name, const char *str)
 
 U_BOOT_CMD(
 	bdinfo,	1,	1,	do_bdinfo,
-	"bdinfo  - print Board Info structure\n",
+	"print Board Info structure",
 	NULL
 );