console: Use printascii for lowlevel debug string

The lowlevel debug with CONFIG_DEBUG_UART has printascii for string
print, and no need to convert to use printch now.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>

common/console.c

@@ -745,11 +745,7 @@ void puts(const char *s)
 	}
 
 	if (IS_ENABLED(CONFIG_DEBUG_UART) && !(gd->flags & GD_FLG_SERIAL_READY)) {
-		while (*s) {
-			int ch = *s++;
-
-			printch(ch);
-		}
+		printascii(s);
 		return;
 	}