CBMEM: Implement cbmem_run_init_hooks() stub

Until we completely can unify early_variables, use these to
handle CBMEM update hooks for both romstage and ramstage.

For x86, CAR_MIGRATE serves the purpose of romstage hooks.

Change-Id: I100ebc0e35e1b7091b4f287ca37f539fd7c9fa7a
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7876
Reviewed-by: Aaron Durbin <adurbin@google.com>
Tested-by: build bot (Jenkins)

src/lib/cbmem_common.c

@@ -47,3 +47,14 @@ void cbmem_print_entry(int n, u32 id, u64 base, u64 size)
 }
 
 #endif /* !__PRE_RAM__ */
+
+/* FIXME: Replace with CBMEM_INIT_HOOKS API. */
+#if !IS_ENABLED(CONFIG_ARCH_X86)
+void cbmem_run_init_hooks(void)
+{
+}
+
+void __attribute__((weak)) cbmem_fail_resume(void)
+{
+}
+#endif