lib: utils: serial: Initial commit of xlnx-uartlite

Initial commit of the xlnx-uartlite device and FDT support. This was
tested by running OpenSBI on a modified QEMU virt machine using the
xlnx-uartlite for serial.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

include/sbi_utils/fdt/fdt_helper.h

@@ -68,6 +68,9 @@ int fdt_parse_uart8250_node(void *fdt, int nodeoffset,
 int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
 		       const char *compatible);
 
+int fdt_parse_xlnx_uartlite_node(void *fdt, int nodeoffset,
+			       struct platform_uart_data *uart);
+
 struct aplic_data;
 
 int fdt_parse_aplic_node(void *fdt, int nodeoff, struct aplic_data *aplic);

include/sbi_utils/serial/xlnx_uartlite.h

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Alistair Francis <alistair.francis@wdc.com>
+ */
+#ifndef __SERIAL_XLNX_UARTLITE_H__
+#define __SERIAL_XLNX_UARTLITE_H__
+
+#include <sbi/sbi_types.h>
+
+int xlnx_uartlite_init(unsigned long base);
+
+#endif