arm64: dts: juno: fix cluster sleep state entry latency on all SoC versions

The core and the cluster sleep state entry latencies can't be same as
cluster sleep involves more work compared to core level e.g. shared
cache maintenance.

Experiments have shown on an average about 100us more latency for the
cluster sleep state compared to the core level sleep. This patch fixes
the entry latency for the cluster sleep state.

Fixes: 28e10a8f ("arm64: dts: juno: Add idle-states to device tree")
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: "Jon Medhurst (Tixy)" <tixy@linaro.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>