lisa._assets.kmodules.sched_tp: Add Pixel 6 integrated energy meter support

FEATURE

Allow reading Pixel's 6 energy meter data into an ftrace event.

Also add parsec.h, a parser combinator library as a C header. This is
used to parse sysfs files cleanly with low overhead.

Co-authored-by: Lukasz Luba <lukasz.luba@arm.com>