bsp: k230: add uart driver for cannan

uart is just a temp driver which does not support all uart
controolers.
Later we need to integarate uart_canaan and uart to provide
a full support.

Signed-off-by: Wang Chen <[email protected]>

Author: unicornx

bsp/k230/drivers/interdrv/uart_canaan/SConscript

@@ -0,0 +1,19 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd     = GetCurrentDir()
+src     = Glob('*.c')
+CPPPATH = [cwd]
+
+group = DefineGroup('Uart', src, depend = ['RT_USING_CANAAN_UART'], CPPPATH = CPPPATH)
+
+objs = [group]
+
+list = os.listdir(cwd)
+
+for item in list:
+    if os.path.isfile(os.path.join(cwd, item, 'SConscript')):
+        objs = objs + SConscript(os.path.join(item, 'SConscript'))
+
+Return('objs')