Initialize platform for MediaTek mt8192

- Add basic platform setup
- Add mt8192 documentation at docs/plat/
- Add generic CPU helper functions
- Add basic register address

Change-Id: Ife34622105404a8227441aab939e3c55c96374e9
diff --git a/plat/mediatek/mt8192/plat_pm.c b/plat/mediatek/mt8192/plat_pm.c
new file mode 100644
index 0000000..81a170d
--- /dev/null
+++ b/plat/mediatek/mt8192/plat_pm.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2020, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/* common headers */
+#include <lib/psci/psci.h>
+
+/* mediatek platform specific headers */
+
+
+/*******************************************************************************
+ * MTK_platform handler called when an affinity instance is about to be turned
+ * on. The level and mpidr determine the affinity instance.
+ ******************************************************************************/
+static const plat_psci_ops_t plat_plat_pm_ops = {
+};
+
+int plat_setup_psci_ops(uintptr_t sec_entrypoint,
+			const plat_psci_ops_t **psci_ops)
+{
+	*psci_ops = &plat_plat_pm_ops;
+
+	return 0;
+}