Add lvgl_8.1.0 support for raspberry_pi pico

bsp/raspberry-pico/board/SConscript

@@ -0,0 +1,20 @@
+import os
+import rtconfig
+from building import *
+
+cwd = GetCurrentDir()
+
+# add general drivers
+src = Split('''
+board.c
+''')
+
+path =  [cwd]
+path += [cwd + '/ports/lcd']
+
+if GetDepend(['BSP_USING_LVGL']):
+    path += [cwd + '/ports/lcd']
+
+group = DefineGroup('Drivers', src, depend = [''], CPPPATH = path)
+
+Return('group')