gpu: nova-core: use correct fwsignature for GA100

gpu: nova-core: use correct fwsignature for GA100

Although GA100 uses the same GSP-RM firmware as Turing, it has a different
signature specifically for it.

Fixes: 121ea04cd9f2 ("gpu: nova-core: add support for Turing/GA100 fwsignature")
Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260417191359.1307434-2-ttabi@nvidia.com
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>