Add PCie Master/Serial loopback test to Optimus/Sideswipe
These two files are provided by MindSpeed/FreeScale. 
I have taken out some excessive debug print statements.

Detailed description of the change:
1. This change is for PCIe diagnostics only. That is, one have to configure the
   config spec to include PCIe diagnostics to the barebox image. The diagnostic
   image cannot boot kernel. Normal barebox image will not include these two
   files.
2. The command to run the PCIe loopback is:
   diags -r pcierc
3. These two files are provided by Rajiv from FreeScale. He put in a lot of 
   debug print statements. I commented them out using 
   #ifdef PCIE_DEBUG_LOOPBACK

b/14066775

Change-Id: I0dec72dc568b7b0366afccf8132a4227b5cea155
2 files changed