vfio: Move vfio_spapr_iommu_eeh_ioctl into vfio_iommu_spapr_tce.c

vfio: Move vfio_spapr_iommu_eeh_ioctl into vfio_iommu_spapr_tce.c

As with the previous patch EEH is always enabled if SPAPR_TCE_IOMMU, so
move this last bit of code into the main module.

Now that this function only processes VFIO_EEH_PE_OP remove a level of
indenting as well, it is only called by a case statement that already
checked VFIO_EEH_PE_OP.

This eliminates an unnecessary module and SPAPR code in a global header.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>