Update hex conversion to be compatible with bash version ran on FSP
Update hex conversion to be compatible with bash version ran on FSP

Some changes were done to the hb-memdump.sh script recently that
required us to do a conversion between hex and decimal. This
was only tested on BMC and the code does not work on FSP. This commit
changes that code to something that is logically equivalent but works
on both BMC and FSP.

Change-Id: I08834e154836c3f306a693e0b0b60694afe3e573
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/109585
Reviewed-by: Matt Derksen <7e9f2fc2ed13c4ee3c2ab17f188630a0f557de86@us.ibm.com>
Reviewed-by: Ilya Smirnov <2c7a6ec38cfb553b896499595cca9c656159f2a4@us.ibm.com>
Reviewed-by: Roland Veloz <768fb49134ab823c765de70e7067d9f65f5d0a3e@us.ibm.com>
Tested-by: Jenkins Server <8e3f934e4c44875bc48d33da3ea13d93ba9a233f@us.ibm.com>
Tested-by: Jenkins OP Build CI <e610bd72261d3c0a48f1e8ae36832ab00774d426@us.ibm.com>
Tested-by: Jenkins OP HW <0eb0fff262f74a65a832afbcc7b153e391c9a3fd@us.ibm.com>
Tested-by: Jenkins Combined Simics CI <8312af3886dfc9bb930f549023677220805b137e@us.ibm.com>
Tested-by: FSP CI Jenkins <aa9e4d9ac7cd25905e9c0dd36d4150516e73dd86@us.ibm.com>
Tested-by: Hostboot CI <52521565bd8ea18a2b112942dce4f4220a97c2c8@us.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