ghostscript: update to 9.52

This is maintenance release consolidating the changes introduced
in 9.50. see :
https://www.ghostscript.com/doc/9.52/News.htm



Drop all custom objarch.h files; ghostscript nowadays generates
that with autoconf.

Freetype can no longer be disabled.

Building out of source tree is broken.

Upgrade include several CVE fixes:
CVE-2020-16287
CVE-2020-16288
CVE-2020-16289
CVE-2020-16290
CVE-2020-16291
CVE-2020-16292
CVE-2020-16293
CVE-2020-16294
CVE-2020-16295
CVE-2020-16296
CVE-2020-16297
CVE-2020-16298
CVE-2020-16299
CVE-2020-16300
CVE-2020-16301
CVE-2020-16302
CVE-2020-16303
CVE-2020-16304
CVE-2020-16305
CVE-2020-16308
CVE-2020-16309
CVE-2020-17538

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>