[component] A short OTBN key-usage question

[chchenl]

Description

Hi all,
I am using OTBN alone for its big-number computing power on a project of RSA-SA(signature authentication), where we do not
care that much about 'strict' security.

After reading the document/top-level design files otbn.sv , it seems that sideload keymgr_key could serve as the input of public key, and
the otbn_otp_key could be mainly used for memory scrambling only.

Is the above understanding correct? Is it also OK to set edn_rnd & edn_urnd data bits ='0 or '1? My simulation shows there are assertion-error
checking if these values are 0, 1, or repetitive. I temporarily shut them off.
Thanks for any info.

--vincent