[bsp][nxp]:fix frdm-mcxa156 scons --dist err (#10024)

fix：frdm-mcxa156 scons --dist err

Author: CYFS3

bsp/nxp/mcx/mcxa/frdm-mcxa156/rtconfig.py

@@ -192,7 +192,7 @@
 
 def dist_handle(BSP_ROOT, dist_dir):
     cwd_path = os.getcwd()
-    sys.path.append(os.path.join(os.path.dirname(BSP_ROOT), 'tools'))
+    sys.path.append(os.path.join(os.path.dirname(BSP_ROOT), '..', 'tools'))
     from sdk_dist import dist_do_building
     dist_do_building(BSP_ROOT, dist_dir)