iommu/amd: Rearrange attach device code

attach_device() is just holding lock and calling do_attach(). There is
not need to have another function. Just move do_attach() code to
attach_device(). Similarly move do_detach() code to detach_device().

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241030063556.6104-9-vasant.hegde@amd.com


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