modules: hal_nxp: fix camke for sdk-ng middleware

As middleware.cmake could be included by mcux-sdk's CMakeLists.txt,
so use CMAKE_CURRENT_LIST_DIR to make sure the directory is correct.

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
Signed-off-by: Jony Zhang <jony.zhang@nxp.com>