radeonsi: add new polaris12 pci id

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: 17.0 17.1 <mesa-stable@lists.freedesktop.org>

include/pci_ids/radeonsi_pci_ids.h

@@ -213,6 +213,7 @@ CHIPSET(0x6985, POLARIS12_, POLARIS12)
 CHIPSET(0x6986, POLARIS12_, POLARIS12)
 CHIPSET(0x6987, POLARIS12_, POLARIS12)
 CHIPSET(0x6995, POLARIS12_, POLARIS12)
+CHIPSET(0x6997, POLARIS12_, POLARIS12)
 CHIPSET(0x699F, POLARIS12_, POLARIS12)
 
 CHIPSET(0x6860, VEGA10_, VEGA10)