添加rtthread相关代码

riscv/rtthread/components/drivers/usb/usbdevice/SConscript

@@ -0,0 +1,38 @@
+Import('RTT_ROOT')
+from building import *
+
+cwd = GetCurrentDir()
+src = Split("""
+core/usbdevice_core.c
+core/usbdevice.c
+""")
+
+if GetDepend('RT_USB_DEVICE_CDC'):
+    src += Glob('class/cdc_vcom.c')
+
+if GetDepend('RT_USB_DEVICE_HID'):
+    src += Glob('class/hid.c')
+
+if GetDepend('RT_USB_DEVICE_MSTORAGE'):
+    src += Glob('class/mstorage.c')
+
+if GetDepend('RT_USB_DEVICE_ECM'):
+    src += Glob('class/ecm.c')
+
+if GetDepend('RT_USB_DEVICE_RNDIS'):
+    src += Glob('class/rndis.c')
+
+if GetDepend('RT_USB_DEVICE_WINUSB'):
+    src += Glob('class/winusb.c')
+
+if GetDepend('RT_USB_DEVICE_AUDIO_MIC'):
+    src += Glob('class/audio_mic.c')
+
+if GetDepend('RT_USB_DEVICE_AUDIO_SPEAKER'):
+    src += Glob('class/audio_speaker.c')
+
+CPPPATH = [cwd]
+
+group = DefineGroup('rt_usbd', src, depend = ['RT_USING_USB_DEVICE'], CPPPATH = CPPPATH)
+
+Return('group')