feat(zlib): update zlib source files

Upgrade the zlib source files to the ones present in the version 1.2.13
of zlib [1]. Since 1.2.11 the use of Arm crc32 instructions has been
introduced so update the files to make use of this.

[1] https://github.com/madler/zlib/tree/v1.2.13



Change-Id: Ideef78c56f05ae7daec390d00dcaa8f66b18729e
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>