From: Martine Silbermann <Martine.Silbermann@hp.com>

Having spent a non trivial amount of time trying to pull in the code to
enable MSI, I would suggest that a clear indication in Kconfig that MSI
requires CONFIG_PCI_USE_VECTOR would be very helpful.  Also since the MSI
code was integrated into 2.6.1 I've updated the comment that called for
installing the MSI patch.