mach-ipq40xx: add CPU specific code

Provide basic DRAM info population from DT, cache setting and the
board_init stub.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Acked-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

arch/arm/mach-ipq40xx/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2024 Sartura Ltd.
+#
+# Author: Robert Marko <robert.marko@sartura.hr>
+
+obj-y += cpu.o

arch/arm/mach-ipq40xx/cpu.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CPU code for Qualcomm IPQ40xx SoC
+ *
+ * Copyright (c) 2024 Sartura Ltd.
+ *
+ * Author: Robert Marko <robert.marko@sartura.hr>
+ */
+
+#include <cpu_func.h>
+#include <init.h>
+
+int dram_init(void)
+{
+	int ret;
+
+	ret = fdtdec_setup_memory_banksize();
+	if (ret)
+		return ret;
+	return fdtdec_setup_mem_size_base();
+}
+
+/*
+ * Enable/Disable D-cache.
+ * I-cache is already enabled in start.S
+ */
+void enable_caches(void)
+{
+	dcache_enable();
+}
+
+void disable_caches(void)
+{
+	dcache_disable();
+}
+
+/*
+ * In case boards need specific init code, they can override this stub.
+ */
+int __weak board_init(void)
+{
+	return 0;
+}