ARM: ep93xx: activate NO_HZ and high-res timers

Let's set the EP93xx to NO_HZ mode and activate the high-res
timers now that we have GENERIC_CLOCKEVENTS.
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/configs/ep93xx_defconfig

 CONFIG_SYSVIPC=y
+CONFIG_NO_HZ_IDLE=y
+CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_LOG_BUF_SHIFT=14