PCI/DOE: Rename Discovery Response Data Object Contents to type

PCI/DOE: Rename Discovery Response Data Object Contents to type

PCIe r6.1, sec 6.30.1.1, describes a "Vendor ID", a "Data Object Type" and
"Next Index" as the fields in the DOE Discovery Response Data Object. The
DOE driver currently uses both the terms 'type' and 'prot' for the second
element.

Rename all uses of the DOE Discovery Response Data Object to use 'type' as
the second element of the object header, instead of type/prot as it
currently is.

Link: https://lore.kernel.org/r/20250306075211.1855177-2-alistair@alistair23.me
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>