Add some more MMIO, smcCpuOn

exosphere/pmc.c

@@ -0,0 +1,11 @@
+#include "pmc.h"
+
+volatile void *g_pmc_registers = NULL;
+
+void set_pmc_address(void *pmc_base) {
+    g_pmc_registers = pmc_base;
+}
+
+inline void *get_pmc_address(void) {
+    return g_pmc_registers;
+}