libsepol: bump to version 2.8

libsepol: bump to version 2.8

- Remove first patch (already in version):
  https://github.com/SELinuxProject/selinux/commit/f8532f17731c82df9956aa1c92f7fb08bd65bf05
- Update second and third patch
- For target variant, set SHLIBDIR=/usr/lib because by default it is set
  to /lib and LIBDIR is set to $(PREFIX)/lib (with PREFIX=/usr)
- For host variant, set SHLIBDIR=$(HOST_DIR)/lib otherwise shared
  library will be installed in /lib (PREFIX is not used to install
  shared library)
- Add hash for license file

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>