[coreboot] Re Dell Optiplex GX1 support

[Anders Jenbo]

To improve the support a bit navigate to coreboot/util/getpir/ and run
make, then run ./getpir (on the GX1), this will generate a irq_tables.c
file. Copy it to your folder, and add the following to the first section
of your Kconfig.

	select HAVE_PIRQ_TABLE

Once you have done this you should be ready to compile CoreBoot and
flash it on to your board.
If the flashing fails or the compiled ROM doesn't work for your board
could be unable to boot, so it is strongly recommended that you find or
buy a similar ROM chip so that you have a working backup in case
something goes wrong.

-Anders