PCI: Make the intel-iommu_wait_op macro work when jiffies are not running

PCI: Make the intel-iommu_wait_op macro work when jiffies are not running

The following patch changes the intel-iommu.c code to use the TSC
instead of jiffies for detecting bad DMAR functionality.  Some systems
with bad bios's have been seen to hang in early boot spinning in the
IOMMU_WAIT_IO macro.  This patch will replace the infinite loop with a call to
panic.

Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>