I had the same problem in my p35 board.
What i did was redo the entire process but on step 5 not flash the bios only the firmware.
i.e
instead of
sas2flsh.exe -l Flashlog.txt -o -f 2118ir.bin -b mptsas2.rom
do
sas2flsh.exe -l Flashlog.txt -o -f 2118ir.bin
this will cause your controller no to display anything at boot time but still work as a controller in unraid (also boots faster this way).