dm: Add a panic_str() function to reduce code size

The printf() in panic() adds about 1.5KB of code size to SPL when compiled
with Thumb-2. Provide a smaller version that does not support printf()-style
arguments and use it in two commonly compiled places.

Signed-off-by: Simon Glass <sjg@chromium.org>

lib/vsprintf.c

@@ -842,13 +842,11 @@ int sprintf(char *buf, const char *fmt, ...)
 	return i;
 }
 
-void panic(const char *fmt, ...)
+static void panic_finish(void) __attribute__ ((noreturn));
+
+static void panic_finish(void)
 {
-	va_list args;
-	va_start(args, fmt);
-	vprintf(fmt, args);
 	putc('\n');
-	va_end(args);
 #if defined(CONFIG_PANIC_HANG)
 	hang();
 #else
@@ -859,6 +857,21 @@ void panic(const char *fmt, ...)
 		;
 }
 
+void panic_str(const char *str)
+{
+	puts(str);
+	panic_finish();
+}
+
+void panic(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	vprintf(fmt, args);
+	va_end(args);
+	panic_finish();
+}
+
 void __assert_fail(const char *assertion, const char *file, unsigned line,
 		   const char *function)
 {