Fix issue when decoding a string when in fact the string is binary data
Fix issue when decoding a string when in fact the string is binary data

There is an issue when the data to decode is expected to be a string
but in fact it is binary so hostfw_trace.py will return error:
'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
Error processing binary file version 1 - terminating

This fix puts a try block around the decoding of the string and will
catch any failures.  Any failures will displayed to user:

"Warnings": [
    "Issue with parsing argument 3 with data '0xFFFFFF' for:",
    "  string: pullTraceBuildInfo: image build date = %8d, build time = %04d,
   build tag = %-.20s", <-- This would be appended above, but exceeds line limit
    "  source: ../utilxipimage.C"

Change-Id: If3dcc72c02e58eff7655721b320debb2de2aa722
CQ: SW548375
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/130386
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins Combined Simics CI <8312af3886dfc9bb930f549023677220805b137e@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Tested-by: Jenkins OP HW <0eb0fff262f74a65a832afbcc7b153e391c9a3fd@us.ibm.com>
Tested-by: Hostboot CI <52521565bd8ea18a2b112942dce4f4220a97c2c8@us.ibm.com>
Reviewed-by: Isaac Salem <c69ff4695291efa8bfa4efde6e5e177cdf719186@ibm.com>
Reviewed-by: Zachary Clark <9de8c4480303b5335cd2a33eefe814615ba3612a@ibm.com>
Reviewed-by: Daniel M Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot