git: define NO_PYTHON=1 to stop git requiring python as a dependancy

git: define NO_PYTHON=1 to stop git requiring python as a dependancy

Git requires python by default as an included script to link git
to perforce is written in Python. Define NO_PYTHON to stop the
script being included and thus remove the dependancy on Python.

(From OE-Core rev: 602538e1c8403e8b188109ce94a906a1d9090d7e)

Signed-off-by: Jack Mitchell <jack.mitchell@dbbroadcast.co.uk>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>