selftests: intel_pstate: ftime() is deprecated

Use clock_gettime() instead of deprecated ftime().

aperf.c: In function ‘main’:
aperf.c:58:2: warning: ‘ftime’ is deprecated [-Wdeprecated-declarations]
58 | ftime(&before);
| ^~~~~
In file included from aperf.c:9:
/usr/include/sys/timeb.h:39:12: note: declared here
39 | extern int ftime (struct timeb *__timebuf)
| ^~~~~

Signed-off-by: Tommi Rantala <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/intel_pstate/aperf.c

···
 #include <sched.h>
 #include <errno.h>
 #include <string.h>
+#include <time.h>
 #include "../kselftest.h"
+
+#define MSEC_PER_SEC	1000L
+#define NSEC_PER_MSEC	1000000L
 
 void usage(char *name) {
 	printf ("Usage: %s cpunum\n", name);
···
 	long long tsc, old_tsc, new_tsc;
 	long long aperf, old_aperf, new_aperf;
 	long long mperf, old_mperf, new_mperf;
-	struct timeb before, after;
+	struct timespec before, after;
 	long long int start, finish, total;
 	cpu_set_t cpuset;
 
···
 		return 1;
 	}
 
-	ftime(&before);
+	if (clock_gettime(CLOCK_MONOTONIC, &before) < 0) {
+		perror("clock_gettime");
+		return 1;
+	}
 	pread(fd, &old_tsc,  sizeof(old_tsc), 0x10);
 	pread(fd, &old_aperf,  sizeof(old_mperf), 0xe7);
 	pread(fd, &old_mperf,  sizeof(old_aperf), 0xe8);
···
 		sqrt(i);
 	}
 
-	ftime(&after);
+	if (clock_gettime(CLOCK_MONOTONIC, &after) < 0) {
+		perror("clock_gettime");
+		return 1;
+	}
 	pread(fd, &new_tsc,  sizeof(new_tsc), 0x10);
 	pread(fd, &new_aperf,  sizeof(new_mperf), 0xe7);
 	pread(fd, &new_mperf,  sizeof(new_aperf), 0xe8);
···
 	aperf = new_aperf-old_aperf;
 	mperf = new_mperf-old_mperf;
 
-	start = before.time*1000 + before.millitm;
-	finish = after.time*1000 + after.millitm;
+	start = before.tv_sec*MSEC_PER_SEC + before.tv_nsec/NSEC_PER_MSEC;
+	finish = after.tv_sec*MSEC_PER_SEC + after.tv_nsec/NSEC_PER_MSEC;
 	total = finish - start;
 
-	printf("runTime: %4.2f\n", 1.0*total/1000);
+	printf("runTime: %4.2f\n", 1.0*total/MSEC_PER_SEC);
 	printf("freq: %7.0f\n", tsc / (1.0*aperf / (1.0 * mperf)) / total);
 	return 0;
 }