ami: fix eventfd_signal() build on RHEL 9.5+

[amd-vserbu]

Fixes #33

Extend the eventfd_signal() preprocessor gate in sw/AMI/driver/ami_program.c so that the new one-argument form is also selected on RHEL 9.5+ and its rebuilds (Rocky Linux 9.5+, AlmaLinux 9.5+, …), where Red Hat backported the upstream v6.8 eventfd_signal() simplification into the 5.14-based kernel. See the linked issue for the full root-cause and reproduction.

Before:

#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 8, 0)
    eventfd_signal(efd_ctx);
#else
    eventfd_signal(efd_ctx, bytes_to_write);
#endif

After:

#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 8, 0) || \
    (defined(RHEL_RELEASE_CODE) && RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(9, 5))
    eventfd_signal(efd_ctx);
#else
    eventfd_signal(efd_ctx, bytes_to_write);
#endif

The same change is applied to the second eventfd_signal() call site (the boot-tag rewrite path), so the two gates stay in sync.

The form chosen here, defined(RHEL_RELEASE_CODE) && RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(9, 5), is the same idiom already used by this driver in sw/AMI/driver/ami_cdev.c for the class_create() / devnode() signature change, so it's consistent with existing AVED conventions.

Downstream context

We are currently carrying this fix downstream in SLASH (https://github.com/Xilinx/SLASH) as a sed patch applied in scripts/package-ami.sh right before gen_package.py is invoked, and reverted on exit:

# Extend the eventfd_signal() version gate in ami_program.c so the
# void-arg form is also picked up on RHEL 9.5+, which is when Red Hat
# backported the upstream 6.8 eventfd_signal() simplification into the
# 5.14-based kernel.
sed -i 's@#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 8, 0)$@#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 8, 0) || (defined(RHEL_RELEASE_CODE) \&\& RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(9, 5))@' "${AMI_PROGRAM_C}"

The sed produces exactly the diff in this PR, and we have verified it works: with the patch applied, gen_package.py produces a working ami-*.rpm whose ami.ko builds with DKMS and loads cleanly on Rocky Linux 9.6 (kernel-5.14.0-570.58.1.el9_6.x86_64). Without it, packaging breaks at compile time on the same machine.

Testing

• Rocky Linux 9.6, kernel-5.14.0-570.58.1.el9_6.x86_64 — fails without this PR, builds + loads with it; PDI download via
  ami_tool works end-to-end and the eventfd progress notifications fire.
• Ubuntu 24.04 (kernel 6.8) — unchanged, still picks the one-arg branch via the LINUX_VERSION_CODE term.