coresight: Fix missing include for FIELD_GET

Include the header for FIELD_GET which is only sometimes transitively
included on some configs and kernel releases.

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lists.linaro.org/archives/list/lkft-triage@lists.linaro.org/thread/6GKMK52PPRJVEYMEUHJP6BXF4CJAXOFL/
Fixes: a4e65842e1 ("coresight: Only check bottom two claim bits")
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250707-james-coresight-bitfield-include-v1-1-aa0f4220ecfd@linaro.org

drivers/hwtracing/coresight/coresight-core.c

@@ -3,6 +3,7 @@
  * Copyright (c) 2012, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/bitfield.h>
 #include <linux/build_bug.h>
 #include <linux/kernel.h>
 #include <linux/init.h>

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -4,6 +4,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/kvm_host.h>

drivers/hwtracing/coresight/coresight-etm4x-sysfs.c

@@ -4,6 +4,7 @@
  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
  */
 
+#include <linux/bitfield.h>
 #include <linux/coresight.h>
 #include <linux/pid_namespace.h>
 #include <linux/pm_runtime.h>

drivers/hwtracing/coresight/ultrasoc-smb.h

@@ -7,6 +7,7 @@
 #ifndef _ULTRASOC_SMB_H
 #define _ULTRASOC_SMB_H
 
+#include <linux/bitfield.h>
 #include <linux/miscdevice.h>
 #include <linux/spinlock.h>