kern: implement uart init + logging

libraries/libmesosphere/source/kern_main.cpp

@@ -35,6 +35,9 @@ namespace ams::kern {
         }
 
         if (core_id == 0) {
+            /* Initialize KSystemControl. */
+            KSystemControl::Initialize();
+
             /* Note: this is not actually done here, it's done later in main after more stuff is setup. */
             /* However, for testing (and to manifest this code in the produced binary, this is here for now. */
             /* TODO: Do this better. */