Suppress errors about undocumented asn1_d2i_read_bio

Suppress errors about undocumented asn1_d2i_read_bio

asn1_d2i_read_bio is exported by libcrypto but is only intended
for internal usage, and does not exist in our public headers.
Therefore we suppress errors about it being a newly added
undocumented symbol.

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14232)