python3: Do not hardcode "lib" for distutils

Get the sys.lib from python3 itself and do not use
hardcoded value of 'lib' for distutils.

Solve the error below that occurs when run "python3 setup.py
install"
on lib64 multilib platform:
[Errno 2] No such file or directory:
'/usr/lib/python3.7/site-packages/test-easy-install-1828.write-test'

(From OE-Core rev: fb33127de5d80f5bcb84edf6cf4007bca73fa863)

Signed-off-by: Li Zhou <li.zhou@windriver.com>

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/python/python3_3.8.1.bb

@@ -30,6 +30,7 @@ SRC_URI = "http://www.python.org/ftp/python/${PV}/Python-${PV}.tar.xz \
            file://0001-setup.py-pass-missing-libraries-to-Extension-for-mul.patch \
            file://0001-Makefile-do-not-compile-.pyc-in-parallel.patch \
            file://0001-configure.ac-fix-LIBPL.patch \
+           file://0001-python3-Do-not-hardcode-lib-for-distutils.patch \
            "
 
 SRC_URI_append_class-native = " \