添加rtthread相关代码

riscv/rtthread/components/drivers/ofw/SConscript

@@ -0,0 +1,25 @@
+from building import *
+
+objs = []
+
+if not GetDepend(['RT_USING_OFW']):
+    Return('objs')
+
+cwd     = GetCurrentDir()
+list    = os.listdir(cwd)
+CPPPATH = [cwd, cwd + '/../include']
+
+src     = Glob('*.c')
+
+if GetDepend('RT_USING_PIC') == False:
+    SrcRemove(src, ['irq.c'])
+
+group = DefineGroup('DeviceDrivers', src, depend = [''], CPPPATH = CPPPATH)
+
+for d in list:
+    path = os.path.join(cwd, d)
+    if os.path.isfile(os.path.join(path, 'SConscript')):
+        objs = objs + SConscript(os.path.join(d, 'SConscript'))
+objs = objs + group
+
+Return('objs')