Small fixes and changes

- Allow printing of more log on HOS boot when LOGS are OFF.
- A small name refactoring
- Add battery warning symbol when battery < 3200mV

bootloader/gfx/gfx.c

@@ -257,7 +257,7 @@ void gfx_putc(char c)
 	}
 }
 
-void gfx_puts(const char *s)
+void gfx_puts(char *s)
 {
 	if (!s || gfx_con.mute)
 		return;