Configuring entropy source for OpenSSL

I’m using OpenSSL 1.0.2 and FOM 2.16 and am trying to figure out a way to draw entropy from Intel (RDRAND/RDSEED) if it’s available, and from the Linux OS (/dev/random or /dev/urandom) if it’s not. If I build OpenSSL with
–with-rand-seed=rdcpu,os
it tries to get entropy first from the Linux OS. I need it to try RDRAND/RDSEED first (for certification reasons), but fall back on the Linux OS if RDRAND/RDSEED isn’t available. Does anyone know a way to do this?