add private key to ipxe

[cckp]

at http://ipxe.org/err/0216eb

>> cat selfsigned-cert.pem selfsigned-key.pem > cert-and-key.pem
>> make bin/ipxe.lkrn EMBED=../syslinux.ipxe CERT=../certs/cert-and-key.pem TRUST=../certs/cert-and-key.pem

this page suggest adding private key to ipxe.lkrn?

I don't see any need to add private key.

when I download file from my testing ssl site, the error code is 0216eb
then after I built with TRUST=myca, the error disappeared.
there seemed to be no need to add private key.