iommu/amd: Restore IRTE.RemapEn bit after programming IRTE

Currently, the RemapEn (valid) bit is accidentally cleared when
programming IRTE w/ guestMode=0. It should be restored to
the prior state.

Fixes: b9fc6b56 ("iommu/amd: Implements irq_set_vcpu_affinity() hook to setup vapic mode for pass-through devices")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200903093822.52012-2-suravee.suthikulpanit@amd.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>