hwrng: Add Zhaoxin rng driver

zhaoxin inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6J139


CVE: NA

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This driver provides kernel-side support for the Random Number
Generator hardware found on Zhaoxin based motherboards.

Signed-off-by: leoliuoc <leoliu-oc@zhaoxin.com>