rust: gem: Introduce DriverObject::Args

rust: gem: Introduce DriverObject::Args

This is an associated type that may be used in order to specify a
data-type to pass to gem objects when constructing them, allowing for
drivers to more easily initialize their private-data for gem objects.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Janne Grunau <j@jananu.net>
Tested-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260316211646.650074-5-lyude@redhat.com
[ Resolve merge conflicts in Tyr. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>