coresight: etm4x: remove duplicated include from coresight-etm4x.c

Remove duplicated include.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-etm4x.c

@@ -33,7 +33,6 @@
 #include <linux/uaccess.h>
 #include <linux/perf_event.h>
 #include <linux/pm_runtime.h>
-#include <linux/perf_event.h>
 #include <asm/sections.h>
 #include <asm/local.h>