defconfig: enable RCU_FAST_NO_HZ for SMP msm targets

RCU_FAST_NO_HZ has been shown to improve power consumption
thanks to CPUs entering nohz idle mode more quickly.

The 7627a and 8660 configurations are omitted until they
can be properly tested with RCU_FAST_NO_HZ.

Change-Id: I4d578ba0496fa46917aa2544fe5314a6d29826fc
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
diff --git a/arch/arm/configs/msm8974_defconfig b/arch/arm/configs/msm8974_defconfig
index ca60319..93f6055 100644
--- a/arch/arm/configs/msm8974_defconfig
+++ b/arch/arm/configs/msm8974_defconfig
@@ -2,6 +2,7 @@
 CONFIG_EXPERIMENTAL=y
 # CONFIG_LOCALVERSION_AUTO is not set
 CONFIG_SYSVIPC=y
+CONFIG_RCU_FAST_NO_HZ=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_CGROUPS=y