To be more uniform with the other new Python classes, rename this to
python_flit_core and update the recipes that use it.
(From OE-Core rev: c0e4ca3c7841028a658f21c11619228022d425b4)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
