add drivers directory.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1797 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/SConscript

+# for module compiling
+import os
+from building import *
+
+cwd  = GetCurrentDir()
+objs = []
+list = os.listdir(cwd)
+
+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'))
+
+Return('objs')

components/usb/SConscript → components/drivers/usb/SConscript

 Import('RTT_ROOT')
 from building import *
 
+cwd     = GetCurrentDir()
 src	= Glob('*.c')
-CPPPATH = [RTT_ROOT + '/components/usb']
+CPPPATH = [cwd]
 group = DefineGroup('USB', src, depend = ['RT_USING_USB_DEVICE'], CPPPATH = CPPPATH)
 
 Return('group')