USB Device Descriptor Max Power is not configurable #504

Replacing hardcoded value with define macro

Author: Props3D

src/arduino/Adafruit_USBD_Device.cpp

@@ -186,7 +186,7 @@ void Adafruit_USBD_Device::clearConfiguration(void) {
   uint8_t const dev_cfg[sizeof(tusb_desc_configuration_t)] = {
       TUD_CONFIG_DESCRIPTOR(1, 0, 0, sizeof(tusb_desc_configuration_t),
                             TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP | TU_BIT(7),
-                            100),
+                            USB_CONFIG_POWER),
   };
 
   memcpy(_desc_cfg_buffer, dev_cfg, sizeof(tusb_desc_configuration_t));