Moderate: kernel security, bug fix, and enhancement update (Oracle Linux 9)

[5.14.0-687.36.1]
- Disable UKI signing [Orabug: 36571828]
- Update Oracle Linux certificates (Kevin Lyons)
- Disable signing for aarch64 (Ilya Okomin)
- Oracle Linux RHCK Module Signing Key was added to the kernel trusted keys list (olkmod_signing_key.pem) [Orabug: 29539237]
- Update x509.genkey [Orabug: 24817676]
- Conflict with shim-ia32 and shim-x64 <= 15.3-1.0.5]
- Remove upstream reference during boot (Kevin Lyons) [Orabug: 34729535]
- Add Oracle Linux IMA certificates
- Add new Oracle Linux Driver Signing (key 1) certificate [Orabug: 37985764]

[5.14.0-687.36.1]
- powerpc/powernv/iommu: iommu incorrectly bypass DMA APIs (Mamatha Inamdar) [RHEL-215575]
- powerpc/iommu: bypass DMA APIs for coherent allocations for pre-mapped memory (Mamatha Inamdar) [RHEL-215575]
- mm/vmscan: add sysctl to limit direct reclaim scanning depth (Audra Mitchell) [RHEL-211058]
- mm/memcg: refactor try_charge_memcg retry logic to use for loop (Audra Mitchell) [RHEL-211058]
- mm/memcg: introduce tunable sysctl for memory cgroup reclaim retries (Audra Mitchell) [RHEL-211058]
- futex: Prevent lockup in requeue-PI during signal/ timeout wakeup (Waiman Long) [RHEL-193526] {CVE-2026-52977}
- futex: Require sys_futex_requeue() to have identical flags (Waiman Long) [RHEL-193526] {CVE-2026-31554}
- futex: Clear stale exiting pointer in futex_lock_pi() retry path (Waiman Long) [RHEL-193526] {CVE-2026-31555}
- futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() (Waiman Long) [RHEL-193526] {CVE-2026-23415}

[5.14.0-687.35.1]
- octeon_ep_vf: add NULL check for napi_build_skb() (CKI Backport Bot) [RHEL-186331]
- octeon_ep_vf: introduce octep_vf_oq_next_idx() helper (CKI Backport Bot) [RHEL-186331]
- octeon_ep_vf: avoid compiler and IQ/OQ reordering (CKI Backport Bot) [RHEL-186331]
- octeon_ep_vf: Relocate counter updates before NAPI (CKI Backport Bot) [RHEL-186331]
- octeon_ep_vf: ensure dbell BADDR updation (CKI Backport Bot) [RHEL-186331]
- net: octeon_ep_vf: fix free_irq dev_id mismatch in IRQ rollback (CKI Backport Bot) [RHEL-186331]
- netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table() (CKI Backport Bot) [RHEL-179745] {CVE-2026-43450}