gpu: nova-core: firmware: factor out an elf_str() function

gpu: nova-core: firmware: factor out an elf_str() function

Factor out a chunk of complexity into a new subroutine. This is an
incremental step in adding ELF32 support to the existing ELF64 section
support, for handling GPU firmware.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260326013902.588242-9-jhubbard@nvidia.com
[acourbot: use fuller prefix in commit message.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>