clocksource/drivers/vt8500: Remove unneeded header

Remove the <asm/time.h> header inclusion which is pointless.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/vt8500_timer.c

@@ -30,7 +30,6 @@
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/delay.h>
-#include <asm/mach/time.h>
 
 #include <linux/of.h>
 #include <linux/of_address.h>