crypto: hisilicon - support querying the capability register

Query the capability register status of accelerator devices
(SEC, HPRE and ZIP) through the debugfs interface, for example:
cat cap_regs. The purpose is to improve the robustness and
locability of hardware devices and drivers.

Signed-off-by: Qi Tao <taoqi10@huawei.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>