package/luajit: switch to moonjit fork

This fork is based on LuaJIT 2.1.0-beta3 which supports ARM64.

The license file is changed with the copyright from the Moonjit
developers, and an additional copy of the MIT license. Therefore the
license terms are still the same: MIT.

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
[Thomas: add details about why the hash of the license file changes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>