plat: Add Kendryte k210 initial support

Only compiles for now, completely untested.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

plat/kendryte/k210/objects.mk

@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2018 Western Digital Corporation or its affiliates.
+#
+# Authors:
+#   Anup Patel <anup.patel@wdc.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+plat-objs-y += uarths.o sysctl.o platform.o