Add PMC support to scratch ram, move makefile targets to new makefile

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

@@ -0,0 +1,32 @@
+#include <scratch/pmc.h>
+
+#define PMC(NUM) { \
+    .status = &PM ## NUM ## STS, \
+    .data_out = &PM ## NUM ## DO, \
+    .data_in = &PM ## NUM ## DI, \
+    .control = &PM ## NUM ## CTL, \
+}
+
+struct Pmc __code PMC_1 = PMC(1);
+
+uint8_t pmc_status(struct Pmc * pmc) {
+    return *(pmc->status);
+}
+
+uint8_t pmc_read(struct Pmc * pmc) {
+    return *(pmc->data_in);
+}
+
+static bool pmc_wait(struct Pmc * pmc, int timeout) {
+    while (pmc_status(pmc) & PMC_STS_OBF) {
+        if (timeout == 0) return false;
+        timeout -= 1;
+    }
+    return true;
+}
+
+bool pmc_write(struct Pmc * pmc, uint8_t data, int timeout) {
+    if (!pmc_wait(pmc, timeout)) return false;
+    *(pmc->data_out) = data;
+    return true;
+}