ARM: shmobile: change dev_id to cpu0 while registering cpu clock

Currently all clkdev registration use "cpufreq-cpu0.0" as dev_id
for cpu clock which refers to virtual platform device. It needs to
be "cpu0" instead which is actual cpu0 device id.

This patch changes the dev_id from "cpufreq-cpu0.0" to "cpu0".

Reported-and-tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Magnus Damm <damm@opensource.se>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>