openeuler: pci: workaround multiple functions can be assigned to only one VM

driver inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I66W4Y


CVE: NA

workaround if multiple functions on a PCl device belong to the same
IOMMU group, they can be directly assigned to only one VM as well,
letting multiple functions belong to different IOMMU group.

Signed-off-by: Duanqiang Wen <duanqiangwen@net-swift.com>
(cherry picked from commit ed2b7e53)