Update MAINTAINERS with location of PCI tree

The PCI tree is now in git at
kernel.org:/pub/scm/linux/kernel/git/jbarnes/pci-2.6.git; add that info to
MAINTAINERS.

MAINTAINERS

@@ -3074,6 +3074,7 @@ P:	Jesse Barnes
 M:	jbarnes@virtuousgeek.org
 L:	linux-kernel@vger.kernel.org
 L:	linux-pci@atrey.karlin.mff.cuni.cz
+T:	git kernel.org:/pub/scm/linux/kernel/git/jbarnes/pci-2.6.git
 S:	Supported
 
 PCI HOTPLUG CORE