It is useful to extend the number of available PCIe devices to KVM guests
for passthrough scenarios and also to expose these models to a different
(big endian) architecture. Introduce a new config PCIE_DEVICES to select
models, Intel Ethernet adapters and one USB controller. These devices all
support MSI-X which is a requirement on s390x as legacy INTx are not
supported.

Cc: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-ID: <20230712080146.839113-1-clg@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>