1. updated to 5.9.0

2. psutil can not be built on macos due to build script detects Darwin
using sys.platform and changes build logic to build for Darwin, but
OpenWrt is Linux.
This commit add patch to allow redefining sys.platform and uses
env var TARGET_SYS_PLATFORM to specify linux as sys platfrom.

Signed-off-by: Sergey V. Lobanov <sergey@lobanov.in>