libplatsupport: omap3 ltimer refactor

This refactors the omap3 ltimer to use the new
driver framework APIs.
- IRQ Chip parser "copied" off avic.c
- Change array-based ABS and REL timer distinction
into two different variables
- gpt_create() sets up mappings, while
abs_gpt_init()/rel_gpt_init() set up the registers
- Change some signatures to void
- IRQ handler moved to timer driver
- IRQ handler logic is shared between 'abs' and
'rel' timers, behaviour differs on how they were
initialised

trivial: use pragma once

Fix whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remove blank lines at end of file

fix licenses

Remove trailing whitespace

libplatsupport: Add absolute timer driver for omap

libplatsupport: Add absolute timer driver for omap