lib: utils/timer: Add Andes fdt timer support

Since we can get the PLMT base address and timer frequency from
device tree, move plmt timer device to fdt timer framework.

dts example (Quad-core AX45MP):

  cpus {
      ...
      timebase-frequency = <0x3938700>;
      ...
  }
  soc {
      ...
      plmt0@e6000000 {
          compatible = "andestech,plmt0";
          reg = <0x00 0xe6000000 0x00 0x100000>;
          interrupts-extended = <&cpu0_intc 0x07
                                 &cpu1_intc 0x07
                                 &cpu2_intc 0x07
                                 &cpu3_intc 0x07>;
      };
      ...
  }

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

lib/utils/timer/fdt_timer_plmt.c

@@ -0,0 +1,51 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Andes Technology Corporation
+ *
+ * Authors:
+ *   Yu Chien Peter Lin <peterlin@andestech.com>
+ */
+
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/timer/fdt_timer.h>
+#include <sbi_utils/timer/andes_plmt.h>
+
+extern struct plmt_data plmt;
+
+static int fdt_plmt_cold_timer_init(void *fdt, int nodeoff,
+				    const struct fdt_match *match)
+{
+	int rc;
+	unsigned long plmt_base;
+
+	rc = fdt_parse_plmt_node(fdt, nodeoff, &plmt_base, &plmt.size,
+				 &plmt.hart_count);
+	if (rc)
+		return rc;
+
+	plmt.time_val = (u64 *)plmt_base;
+	plmt.time_cmp = (u64 *)(plmt_base + 0x8);
+
+	rc = fdt_parse_timebase_frequency(fdt, &plmt.timer_freq);
+	if (rc)
+		return rc;
+
+	rc = plmt_cold_timer_init(&plmt);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static const struct fdt_match timer_plmt_match[] = {
+	{ .compatible = "andestech,plmt0" },
+	{},
+};
+
+struct fdt_timer fdt_timer_plmt = {
+	.match_table = timer_plmt_match,
+	.cold_init   = fdt_plmt_cold_timer_init,
+	.warm_init   = plmt_warm_timer_init,
+	.exit	     = NULL,
+};