This patch series introduces vhost-user-spi device support to QEMU
and synchronizes relevant standard headers from upstream Linux.

The series consists of the following changes:
1. Synchronize virtio_ids.h from Linux kernel (v6.18-rc3) using
   scripts/update-linux-headers.sh.
2. Synchronize virtio_spi.h from Linux kernel (v6.18-rc3) using
   scripts/update-linux-headers.sh.
3. Implement vhost-user-spi and vhost-user-spi-pci devices in QEMU,
   enabling virtio-based SPI communication via the vhost-user protocol.

The new device implementation follows the virtio-spi specification and
leverages the upstream Linux virtio-spi driver. This enables QEMU to emulate
SPI devices using the vhost-user protocol, facilitating integration with external
SPI daemons and improving virtualization support for SPI peripherals.

Signed-off-by: Haixu Cui <quic_haixcui@quicinc.com>