engines/asm/e_padlock*: add support for Zhaoxin's x86 platform

VIA and Shanghai United Investment Co.,Ltd. found Shanghai ZhaoXin,
which is a fabless x86 CPU IC design company. ZhaoXin has issued
ZX-C, ZX-D x86 processors, which have 'Shanghai' CPU vendor id.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5640)