AFAIK, OpenJDK for POWER isn't really done yet. I believe you have to use a JVM from IBM.
the PowerPC/AIX Port of OpenJDK-7 also supports PowerPC/Linux, including Hotspot engine [1]
OpenJDK 1.6 was packaged for Fedora12 PPC; we used it initially for one of our applications but eventually ran into performance problems since IIR there wasn't really a JIT on PPC. We switched to the IBM JDK, which we repackaged locally based on a specfile adapted from (I think) something at JPackage.org.
I dropped the specfile in a gist at https://gist.github.com/063fbd8733ea15e149dc.git, in case you might find it useful.
For RHEL 6.x there are official IBM-JDK packages, but this JVM has, for example, a different implementation of X509, which is incompatible with Sun/Oracle/OpenJDK X509. As we want to have our application as portable as possible and also want to support the hopefully upcoming CentOS-6.6 and CentOS-7 PowerPC platform, we would like to stay on OpenJDK.
Regards, Kai.