Now skips the calibrate_delay loop in the kernel boot

Now skips the calibrate_delay loop in the kernel boot

dev/tsunami.cc:
    Changed so Tsunami has a pointer to the System to which it belongs.
    Now it is derived from generic base class Platform so platform stuff
    can be accessed based on the system
dev/tsunami_io.cc:
dev/tsunami_io.hh:
    Cleanup and added copyright
kern/linux/linux_system.cc:
kern/linux/linux_system.hh:
    Added event to skip the "calibrate_delay" function, now calculate
    loops_per_jiffy based on frequency, interrupt frequency, and constant
sim/system.hh:
    Added pointer to generic Platform base class

--HG--
extra : convert_revision : 5bd925eec220a2ca48eb6164d2ecfdec96922c2c