Implement flashing from scratch rom

src/board/system76/galp3-c/pmc.c

@@ -1,5 +1,6 @@
 #include <board/acpi.h>
 #include <board/pmc.h>
+#include <board/scratch.h>
 #include <common/debug.h>
 
 void pmc_init(void) {
@@ -48,6 +49,12 @@ void pmc_event(struct Pmc * pmc) {
                 // TODO: queue is always empty
                 pmc_write(pmc, 0, PMC_TIMEOUT);
                 break;
+
+            case 0xDC:
+                DEBUG("  scratch rom\n");
+                pmc_write(pmc, 0x33, PMC_TIMEOUT);
+                scratch_trampoline();
+                break;
             }
         } else {
             DEBUG("pmc data: %02X\n", data);