Remove pci-shmem device

The pci-shmem emulated device ("ivshmem") was created by QEMU for
cross-VM data sharing. The only Linux driver that uses this device is
the Android Virtual System on a Chip staging driver, which also mentions
a character device driver implemented on top of shmem, which was removed
from Linux.

On the kvmtool side, the only commits touching the pci-shmem device
since it was introduced in 2012 were made when refactoring various
kvmtool subsystems. Let's remove the maintenance burden on the kvmtool
maintainers and remove this unused device.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
4 files changed