ARM: u300: convert sched_clock() to use new infrastructure

Convert u300 to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ec7b027..d5bd266 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -790,6 +790,7 @@
 	bool "ST-Ericsson U300 Series"
 	depends on MMU
 	select CPU_ARM926T
+	select HAVE_SCHED_CLOCK
 	select HAVE_TCM
 	select ARM_AMBA
 	select ARM_VIC