Add boot addresses for liberty & marvel
Fix liberty machine type
Fix acpu clock init

I *think* this is how it's supposed to be...

Another thing to note is acpuclk_7x27_soc_data has max_speed_delta_khz set to 400000, but liberty's board file had 256000.
Changing it to 256000 doesn't help at the moment (so I didn't commit it), but may be worth trying in the future.