RFR: JDK-8218057 Add ppc64le and s390x profiles to jib-profiles.js

[Magnus Ihse Bursie]

With Volker's fix in JDK-8213698, creating devkits for cross-compiling 
on linux to various other platforms was made trivial.

This patch uses this functionality to add new cross-compilation targets 
for ppc64le and s390x to jib-profiles.js

As usual; this implies no commitment from Oracle to neither build nor 
test on these platforms.

Bug: https://bugs.openjdk.java.net/browse/JDK-8218057
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8218057-add-ppc64le-and-s390x-devkits/webrev.01

/Magnus