Explicitly limit the OPENSSL_aligned_alloc()'s alignment to 65536

Explicitly limit the OPENSSL_aligned_alloc()'s alignment to 65536

There is little need to support alignments larger than a page size,
and the open-coded OPENSSL_aligned_alloc() implementation implements
that support in quite wasteful manner, so it is better just to limit
the maximum supported alignment explicitly.  The value of 65536
has been chosen so it is architecture-agnostic and is no less than page sizes
used in commonly occurring architectures (and also it is a pretty number).

Signed-off-by: Eugene Syromiatnikov <esyr@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28295)