panda: add GM ignition-over-CAN detection on bus 2 (SystemPowerMode 0x1F1)

FrogPilot handles the GM SystemPowerMode message on both bus 0 and bus 2
(SDGM cars send it on bus 2). C3XL-dev only checked bus 0, so GM cars with
0x1F1 on bus 2 never set ignition_can and the device would not auto power-on.
Mirror FrogPilot: check 0x1F1 on bus 2 as well, keep other exceptions bus-0 only.

opendbc_repo/opendbc/safety/ignition.h

@@ -66,6 +66,15 @@ void ignition_can_hook(const CANPacket_t *msg) {
       }
       prev_counter_vw_meb = counter;
     }
+  } else if (msg->bus == 2U) {
+    int len = GET_LEN(msg);
+
+    // GM exception: SDGM cars send SystemPowerMode on bus 2
+    if ((msg->addr == 0x1F1U) && (len == 8)) {
+      // SystemPowerMode (2=Run, 3=Crank Request)
+      ignition_can = (msg->data[0] & 0x2U) != 0U;
+      ignition_can_cnt = 0U;
+    }
   }
 
   // TODO: this is too loose, Teslas have 0x222

panda/board/obj/gitversion.h

@@ -1,2 +1,2 @@
 extern const uint8_t gitversion[19];
-const uint8_t gitversion[19] = "DEV-f3c371b0-DEBUG";
+const uint8_t gitversion[19] = "DEV-22191a15-DEBUG";

panda/board/obj/version

@@ -1 +1 @@
-DEV-f3c371b0-DEBUG
+DEV-22191a15-DEBUG