add sconscript (#1)

SConscript

@@ -0,0 +1,25 @@
+import rtconfig
+Import('RTT_ROOT')
+from building import *
+
+# get current directory
+cwd = GetCurrentDir()
+path = []
+src = []
+
+# The set of source files associated with this SConscript file.
+path += [
+    cwd + '/cyw43-driver/src',
+    cwd + '/cyw43-driver/firmware',
+]
+src += [
+    cwd + '/cyw43-driver/src/cyw43_ctrl.c',
+    cwd + '/cyw43-driver/src/cyw43_ll.c',
+    cwd + '/cyw43-driver/src/cyw43_lwip.c',
+    cwd + '/cyw43-driver/src/cyw43_sdio.c',
+    cwd + '/cyw43-driver/src/cyw43_stats.c',
+]
+
+group = DefineGroup('cyw43-driver', src, depend = ['PKG_USING_CYW43XX'], CPPPATH = path)
+
+Return('group')