CI: hi3516cv500 QEMU regression target for ive_neo

[widgetii]

The QEMU IVE ops regression job in .github/workflows/build.yml runs kernel/ive_neo/test/qemu/test-ive-ops (the vendored 19-op register checksum test) only against the hi3516ev300 machine model in widgetii/qemu-hisilicon. There's no equivalent for cv500.

This means cv500-specific regressions can land without any automated regression catch:

• The PerspTrans + Hog HW handlers from kernel/ive_neo + libraries/ive_neo: cv500 PerspTrans + Hog HW dispatch (default-on) #107 are only verified by on-target tests against openipc-hi3516av300.dlab.doty.ru (not in CI).
• The round-trip test from libraries/ive_neo/test: HW pixel-correctness round-trip for PerspTrans + Hog #108 (libraries/ive_neo/test/test_persp_hog.c) is opt-in and runs on hardware only.

What's needed

1. Upstream QEMU work: widgetii/qemu-hisilicon needs a hi3516cv500 machine model. Doesn't exist yet — separate project.
2. OR: A test runner that ssh's into a CI-attached cv500 board (openipc-hi3516av300.dlab.doty.ru already serves this role for manual verification) and runs test_persp_hog. Needs ssh key + secret in CI.

(2) is more pragmatic short-term — the lab board exists and works; just needs CI access.

Definition of done

• Either:
  • cv500 QEMU machine model exists in qemu-hisilicon AND a QEMU IVE ops regression (cv500) job runs against it; OR
  • A Live cv500 board regression job ssh's to a CI-attached cv500 board (likely behind tailscale / CI runner constraints), loads the freshly built open_ive_neo.ko + libive_neo.so, runs test_persp_hog, asserts Summary: 0 failures.
• The new job is gated on cv500-affecting paths only (kernel/ive_neo/**, libraries/ive_neo/**).

Related

• PR kernel/ive_neo + libraries/ive_neo: cv500 PerspTrans + Hog HW dispatch (default-on) #107 introduces cv500 PerspTrans + Hog HW dispatch.
• PR libraries/ive_neo/test: HW pixel-correctness round-trip for PerspTrans + Hog #108 introduces the round-trip test that this job would run.