top: Rename "plat" to "platform" everywhere

This patch renames "plat" to "platform" everywhere for better
readablility.

Signed-off-by: Anup Patel <anup.patel@wdc.com>

platform/common/include/plat/irqchip/plic.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __IRQCHIP_PLIC_H__
+#define __IRQCHIP_PLIC_H__
+
+#include <sbi/sbi_types.h>
+
+int plic_fdt_fixup(void *fdt, const char *compat);
+
+int plic_warm_irqchip_init(u32 target_hart);
+
+int plic_cold_irqchip_init(unsigned long base,
+			   u32 num_sources, u32 hart_count);
+
+#endif