kvm/vfio: Prepare for accepting vfio device fd

kvm/vfio: Prepare for accepting vfio device fd

[ Upstream commit 2f99073a722beef5f74f3b0f32bda227ba3df1e0 ]

This renames kvm_vfio_group related helpers to prepare for accepting
vfio device fd. No functional change is intended.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-5-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Stable-dep-of: 9e0f4f2918c2 ("kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()")
Signed-off-by: Sasha Levin <sashal@kernel.org>