Please revert the removal of RSA PKCS#1 v1.5 support from cert_tool:

https://github.com/ARM-software/arm-trusted-firmware/commit/6a415a508ea6acec...

We have products shipping with such support.  I think this problem came up before when somebody tried removing such support. They still need to run with the latest yocto codebase.

Regards,  Scott