s390/vdso: ectg gettime support for CLOCK_THREAD_CPUTIME_ID

The code to use the ECTG instruction to calculate the cputime for the
current thread is currently used only for the per-thread CPU-clock
with the clockid -2 (PID=0, VIRT=1). Use the same code for the clockid
CLOCK_THREAD_CPUTIME_ID to speed up the more common clockid as well.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vdso64/clock_gettime.S

@@ -22,7 +22,9 @@ __kernel_clock_gettime:
 	larl	%r5,_vdso_data
 	cghi	%r2,__CLOCK_REALTIME
 	je	4f
-	cghi	%r2,-2		/* CLOCK_THREAD_CPUTIME_ID for this thread */
+	cghi	%r2,__CLOCK_THREAD_CPUTIME_ID
+	je	9f
+	cghi	%r2,-2		/* Per-thread CPUCLOCK with PID=0, VIRT=1 */
 	je	9f
 	cghi	%r2,__CLOCK_MONOTONIC
 	jne	12f