According to the hardware architect, pre-Zen parts support p2p writes and
Zen parts support both p2p reads and writes.

Add entries for Zen parts Raven (0x15d0) and Renoir (0x1630).

Link: https://lore.kernel.org/r/20200406194201.846411-1-alexander.deucher@amd.com


Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>