feat(plat/allwinner): add R329 support

Allwinner R329 is a new dual-core Corte-A53 SoC. Add basical TF-A
support for it, to provide a PSCI implementation containing CPU
boot/shutdown and SoC reset.

Change-Id: I0fa37ee9b4a8e0e1137bf7cf7d614b6ca9624bfe
Signed-off-by: Icenowy Zheng <icenowy@sipeed.com>
diff --git a/plat/allwinner/sun50i_r329/sunxi_power.c b/plat/allwinner/sun50i_r329/sunxi_power.c
new file mode 100644
index 0000000..96a24d5
--- /dev/null
+++ b/plat/allwinner/sun50i_r329/sunxi_power.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2021 Sipeed
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <platform_def.h>
+
+#include <sunxi_mmap.h>
+#include <sunxi_cpucfg.h>
+#include <sunxi_private.h>
+
+int sunxi_pmic_setup(uint16_t socid, const void *fdt)
+{
+	/* Currently known hardware has no PMIC */
+
+	return 0;
+}
+
+void sunxi_power_down(void)
+{
+}
+
+void sunxi_cpu_power_off_self(void)
+{
+	/* TODO: It's still unknown whether CPUIDLE exists on R329 */
+}