ARM: bcmring: convert to sp804 clocksource

bcmring has a set of four sp804 timers incorporated, yet it has its
own copy of the sp804 code.  Convert its clocksource implementation
to the standard sp804 support code.

Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 43f003a..903c9c4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -297,6 +297,7 @@
 	depends on MMU
 	select CPU_V6
 	select ARM_AMBA
+	select ARM_TIMER_SP804
 	select CLKDEV_LOOKUP
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB