gpu: nova-core: don't assume 64-bit firmware images

gpu: nova-core: don't assume 64-bit firmware images

Introduce a single ELF format abstraction that ties each ELF header
type to its matching section-header type. This keeps the shared
section parser ready for upcoming ELF32 support and avoids mixing
32-bit and 64-bit ELF layouts by mistake.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Link: https://patch.msgid.link/20260602032111.224790-8-jhubbard@nvidia.com
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>