drm/ras: Introduce the DRM RAS infrastructure over generic netlink

drm/ras: Introduce the DRM RAS infrastructure over generic netlink

Introduces the DRM RAS infrastructure over generic netlink.

The new interface allows drivers to expose RAS nodes and their
associated error counters to userspace in a structured and extensible
way. Each drm_ras node can register its own set of error counters, which
are then discoverable and queryable through netlink operations. This
lays the groundwork for reporting and managing hardware error states
in a unified manner across different DRM drivers.

Currently it only supports error-counter nodes. But it can be
extended later.

The registration is also not tied to any drm node, so it can be
used by accel devices as well.

It uses the new and mandatory YAML description format stored in
Documentation/netlink/specs/. This forces a single generic netlink
family namespace for the entire drm: "drm-ras".
But multiple-endpoints are supported within the single family.

Any modification to this API needs to be applied to
Documentation/netlink/specs/drm_ras.yaml before regenerating the
code:

$ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
 Documentation/netlink/specs/drm_ras.yaml --mode uapi --header \
 -o include/uapi/drm/drm_ras.h

$ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
  Documentation/netlink/specs/drm_ras.yaml --mode kernel \
  --header -o drivers/gpu/drm/drm_ras_nl.h

$ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
  Documentation/netlink/specs/drm_ras.yaml \
  --mode kernel --source -o drivers/gpu/drm/drm_ras_nl.c

Cc: Zack McKevitt <zachary.mckevitt@oss.qualcomm.com>
Cc: Lijo Lazar <lijo.lazar@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: netdev@vger.kernel.org
Co-developed-by: Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Zack McKevitt <zachary.mckevitt@oss.qualcomm.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patch.msgid.link/20260304074412.464435-8-riana.tauro@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>