add other speed descriptor callback tud_descriptor_other_speed_configuration_cb()

example implement tud_descriptor_device_qualifier_cb() and
tud_descriptor_other_speed_configuration_cb() on high speed device to
fully compliant to usbcv

src/device/usbd.h

@@ -113,9 +113,16 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid);
 TU_ATTR_WEAK uint8_t const * tud_descriptor_bos_cb(void);
 
 // Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
-// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
 TU_ATTR_WEAK uint8_t const* tud_descriptor_device_qualifier_cb(void);
 
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+TU_ATTR_WEAK uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index);
+
 // Invoked when device is mounted (configured)
 TU_ATTR_WEAK void tud_mount_cb(void);