Create tables for cpu info

The CpuInfo packet contains information about cpus (count, name,
frequencies). Two new tables expose that information:
- table "cpu" provides the id / index of a cpu, processor name and
"time_in_state_cpu_id" (id under which time_in_state counts ticks for
the cpu),
- table "cpu_freq" provides available frequencies for a cpu.

The separate cpu id for /proc/pid/time_in_state is needed because ticks
are counted per core cluster. For example on bonito (Pixel 3a XL) there
two clusters: little (cpu0) and big (cpu6).

A follow-up CL will make use of this to correctly count time_in_state.

Bug: 157216280
Test: tools/diff_test_trace_processor.py
Change-Id: I3cfe23aea6e180b21bd88a5e6a6409537ee5a912