[UBUNTU 23.04] Kernel config option missing for s390 PCI passthrough

=== Description by <email address hidden> ===

LP#1853306 / IBM bug 182254 backported the necessary kernel pieces to enable enhanced interpretation of PCI passthrough on s390. It also included a kernel config update for CONFIG_VFIO_PCI_ZDEV_KVM=y which is necessary to activate this kernel feature.

For lunar and mantic, the kernel code did not require backporting due to the base kernel version already containing it, but the kernel config option still needs to be enabled. Comparison from git.launchpad.net:

Jammy:
cat debian.master/config/annotations | grep CONFIG_VFIO_PCI_ZDEV_KVM
CONFIG_VFIO_PCI_ZDEV_KVM policy<{'s390x': 'y'}>
CONFIG_VFIO_PCI_ZDEV_KVM note<'LP#1853306 Enable VFIO zPCI pass-through for s390x'>

Lunar:
cat debian.master/config/annotations | grep CONFIG_VFIO_PCI_ZDEV_KVM
CONFIG_VFIO_PCI_ZDEV_KVM policy<{'s390x': 'n'}>

Mantic:
cat debian.master/config/annotations | grep CONFIG_VFIO_PCI_ZDEV_KVM
CONFIG_VFIO_PCI_ZDEV_KVM policy<{'s390x': 'n'}>

This setting is supposed to default y when S390 && KVM via Kconfig. Can this be enabled for lunar, mantic, and future releases?