package/freetype: bump version to 2.8

package/freetype: bump version to 2.8

Added md5 & sha1 hashes supplied by sourceforge mirror.

Removed patches applied upstream:

0001-psaux-Better-protect-flex-handling.patch
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=f958c48ee431bef8d4d466b40c9cb2d4dbcb7791

0002-src-psaux-psobjs.c-t1_builder_close_contour-Add-safe.patch
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=3774fc08b502c3e685afca098b6e8a195aded6a0

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>