PXE ISR: Force polling on select hardware WORKAROUND
By OUI == 00:23:ae and flags == 0xdc1b, detect select hardware.
On select platforms (Dell OptiPlex 760, Dell OptiPlex 960; perhaps
more), the interrupt appears to go "deaf" after a few seconds. By
matching MAC OUI and flags value, force polling on these select
platforms. I'm not sure if there's any better data available that
shallow in the core. I believe PCI IDs can be fetched with functions
from other libraries and the UUID and DMI data (the most likely to be
useful is SYSPRODUCT) is available in ldlinux.c32.
Commit message expanded with Matt Fleming's assistance
Signed-off-by: Gene Cumm <gene.cumm@gmail.com>