tools/power/x86/intel-speed-select: Print friendly warning for bad command line

When user specifies invalid option, display "Unknown Option: ignore",
instead of "no match". Also display error for garbage on the command
line.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

tools/power/x86/intel-speed-select/isst-config.c

@@ -2400,9 +2400,12 @@ static void parse_cmd_args(int argc, int start, char **argv)
 			}
 			break;
 		default:
-			printf("no match\n");
+			printf("Unknown option: ignore\n");
 		}
 	}
+
+	if (argv[optind])
+		printf("Garbage at the end of command: ignore\n");
 }
 
 static void isst_help(void)