cpu: add & enable overclocking, [read more...]

Add additional L2 step with more bandwidth and higher freq,
allow uv to 800mv
allow ov to 1450mv
max clock: 1944Mhz

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
acpu/board: lower min constraints further and fix max constraints for cpu uv/ov

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>