vfio/spapr: Move VFIO_CHECK_EXTENSION into tce_iommu_ioctl()

The PPC64 kconfig is a bit of a rats nest, but it turns out that if
CONFIG_SPAPR_TCE_IOMMU is on then EEH must be too:

config SPAPR_TCE_IOMMU
	bool "sPAPR TCE IOMMU Support"
	depends on PPC_POWERNV || PPC_PSERIES
	select IOMMU_API
	help
	  Enables bits of IOMMU API required by VFIO. The iommu_ops
	  is not implemented as it is not necessary for VFIO.

config PPC_POWERNV
	select FORCE_PCI

config PPC_PSERIES
	select FORCE_PCI

config EEH
	bool
	depends on (PPC_POWERNV || PPC_PSERIES) && PCI
	default y

So, just open code the call to eeh_enabled() into tce_iommu_ioctl().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>