parisc: Switch to generic sched_clock implementation

Drop the open-coded sched_clock() function and replace it by the provided
GENERIC_SCHED_CLOCK implementation.  We have seen quite some hung tasks in the
past, which seem to be fixed by this patch.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 71c4a3a..a14b865 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -34,7 +34,9 @@
 	select HAVE_ARCH_HASH
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
-	select HAVE_UNSTABLE_SCHED_CLOCK if (SMP || !64BIT)
+	select GENERIC_SCHED_CLOCK
+	select HAVE_UNSTABLE_SCHED_CLOCK if SMP
+	select GENERIC_CLOCKEVENTS
 	select ARCH_NO_COHERENT_DMA_MMAP
 	select CPU_NO_EFFICIENT_FFS