The source code and links to the source code are actually available to you right now.
Look here:
C:\NXP\S32DS_Power_v2.1\S32DS\build_tools\powerpc-eabivle-4_9\patches_applied
This contains patch files (i.e. all our internal changes) for all the base packages used to build GCC for Power. A list of base package links are located in:
C:\NXP\S32DS_Power_v2.1\S32DS\build_tools\powerpc-eabivle-4_9\patches_applied/FREESCALE_SOURCES
Downloading all the base packages and then applying the patch files to the sources will give you the exact copy of our Power Architecture builds. You can reuse build scripts from the previous used source build.
Hope this helps.