p11-kit: take source code from official git
The previous tarball URI seems to be gone.
Also, adjust a few things to make it actually build;
handling autotools-based projects from git checkouts is always harder
than taking them from tarballs :-(
(From OE-Core rev:
b4542e867d54c56e6ef088fac28ae3d5e6c0d7bc)
Signed-off-by: Alexander Kanavin <alexander.kanavin@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
