ghostscript: 9.21 -> 9.23

ghostscript: 9.21 -> 9.23

1. Drop backported patches
- CVE-2017-7207.patch
- CVE-2017-5951.patch
- CVE-2017-7975.patch
- CVE-2017-9216.patch
- CVE-2017-9611.patch
- CVE-2017-9612.patch
- CVE-2017-9739.patch
- CVE-2017-9726.patch
- CVE-2017-9727.patch
- CVE-2017-9835.patch
- CVE-2017-11714.patch

2. Rebase to 9.23
- ghostscript-9.15-parallel-make.patch
- ghostscript-9.16-Werror-return-type.patch
- do-not-check-local-libpng-source.patch
- avoid-host-contamination.patch
- mkdir-p.patch
- ghostscript-9.21-prevent_recompiling.patch
- ghostscript-9.02-genarch.patch
- cups-no-gcrypt.patch
- ghostscript-9.21-native-fix-disable-system-libtiff.patch
- base-genht.c-add-a-preprocessor-define-to-allow-fope.patch

3. Add packps from (native to target) to support cross compiling.

4. Add remove-direct-symlink.patch to fix
   do_populate_sysroot failure

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>