ARM: shmobile: r8a73a4: Remove ->init_machine() special case

No need to special case r8a73a4 ->init_machine(),
so get rid of undesired cpufreq platform device
from the generic long term r8a73a4 DT support code.

For short term support on APE6EVM the DT reference
implementation already adds a "cpufreq-cpu0" platform
device so that can be used for development.

Regarding more long term cpufreq support, perhaps
it makes sense to adjust the cpufreq driver to check
for DT information directly instead of using a
platform device for software configuration and DT
for hardware parameters.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>