Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-iop32x/pmu.c b/arch/arm/mach-iop32x/pmu.c
new file mode 100644
index 0000000..bdbc7a3
--- /dev/null
+++ b/arch/arm/mach-iop32x/pmu.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PMU IRQ registration for the iop3xx xscale PMU families.
+ * Copyright (C) 2010 Will Deacon, ARM Ltd.
+ */
+
+#include <linux/platform_device.h>
+#include "irqs.h"
+
+static struct resource pmu_resource = {
+	.start	= IRQ_IOP32X_CORE_PMU,
+	.end	= IRQ_IOP32X_CORE_PMU,
+	.flags	= IORESOURCE_IRQ,
+};
+
+static struct platform_device pmu_device = {
+	.name		= "xscale-pmu",
+	.id		= -1,
+	.resource	= &pmu_resource,
+	.num_resources	= 1,
+};
+
+static int __init iop3xx_pmu_init(void)
+{
+	platform_device_register(&pmu_device);
+	return 0;
+}
+
+arch_initcall(iop3xx_pmu_init);