ARM: sa1100: convert sched_clock() to use new infrastructure

Convert sa1100 to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 23035d6..0e1a966 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -642,6 +642,7 @@
 	select CPU_FREQ
 	select GENERIC_CLOCKEVENTS
 	select HAVE_CLK
+	select HAVE_SCHED_CLOCK
 	select TICK_ONESHOT
 	select ARCH_REQUIRE_GPIOLIB
 	help