allwinner: Add Allwinner H6 SoC support

The H6 is Allwinner's most recent SoC. It shares most peripherals with the
other ARMv8 Allwinner SoCs (A64/H5), but has a completely different memory
map.

Introduce a separate platform target, which includes a different header
file to cater for the address differences. Also add the new build target
to the documentation.

The new ATF platform name is "sun50i_h6".

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/allwinner/sun50i_h6/include/sunxi_cpucfg.h b/plat/allwinner/sun50i_h6/include/sunxi_cpucfg.h
new file mode 100644
index 0000000..e061b89
--- /dev/null
+++ b/plat/allwinner/sun50i_h6/include/sunxi_cpucfg.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __SUNXI_CPUCFG_H__
+#define __SUNXI_CPUCFG_H__
+
+#include <sunxi_mmap.h>
+
+/* c = cluster, n = core */
+#define SUNXI_CPUCFG_CLS_CTRL_REG0(c)	(SUNXI_CPUCFG_BASE + 0x0010 + (c) * 0x10)
+#define SUNXI_CPUCFG_CLS_CTRL_REG1(c)	(SUNXI_CPUCFG_BASE + 0x0014 + (c) * 0x10)
+#define SUNXI_CPUCFG_CACHE_CFG_REG	(SUNXI_CPUCFG_BASE + 0x0024)
+#define SUNXI_CPUCFG_DBG_REG0		(SUNXI_CPUCFG_BASE + 0x00c0)
+
+#define SUNXI_CPUCFG_RST_CTRL_REG(c)	(SUNXI_CPUCFG_BASE + 0x0000 + (c) * 4)
+#define SUNXI_CPUCFG_RVBAR_LO_REG(n)	(SUNXI_CPUCFG_BASE + 0x0040 + (n) * 8)
+#define SUNXI_CPUCFG_RVBAR_HI_REG(n)	(SUNXI_CPUCFG_BASE + 0x0044 + (n) * 8)
+
+#define SUNXI_POWERON_RST_REG(c)	(SUNXI_R_CPUCFG_BASE + 0x0040 + (c) * 4)
+#define SUNXI_POWEROFF_GATING_REG(c)	(SUNXI_R_CPUCFG_BASE + 0x0044 + (c) * 4)
+#define SUNXI_CPU_POWER_CLAMP_REG(c, n)	(SUNXI_R_CPUCFG_BASE + 0x0050 + \
+					(c) * 0x10 + (n) * 4)
+
+#endif /* __SUNXI_CPUCFG_H__ */