iommu/amd: Enable ga_log_intr when enabling guest_mode

IRTE[GALogIntr] bit should set when enabling guest_mode, which enables
IOMMU to generate entry in GALog when IRTE[IsRun] is not set, and send
an interrupt to notify IOMMU driver.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org # v4.9+
Fixes: d98de49a

 ('iommu/amd: Enable vAPIC interrupt remapping mode by default')
Signed-off-by: Joerg Roedel <jroedel@suse.de>