altos: Allow devices to override default beep

New beeper will want new default.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/kernel/ao_beep.h b/src/kernel/ao_beep.h
index 8c5d53435254df11e78ad3c311c6c04fc4de1d3b..1dbc9456c117d8c03dc6bc400803e1aa1d68c9ea 100644 (file)
--- a/src/kernel/ao_beep.h
+++ b/src/kernel/ao_beep.h
@@ -35,7 +35,9 @@
  * frequency = 1/2 (24e6/32) / beep
  */
 
+#ifndef AO_BEEP_MID_DEFAULT
 #define AO_BEEP_MID_DEFAULT    94      /* 3989Hz */
+#endif
 
 #if HAS_BEEP_CONFIG
 #define AO_BEEP_MID    ao_config.mid_beep