Inline timer init functions, no static storage

Hardware init function profit a great deal from being inlined if the
given parameters are constant -- which is the common use-case, we could
probably call this for all timers and still have less overhead. The
hwtimer_pwm_ini (which calls hwtimer_ini) gets completely computed at
compile-time resulting only in the register settings of hwtimer_ini.

This is now possible because we get rid of static storage for the
max_ticks and instead compute this in hwtimer_pwm_max_ticks from the
timer register settings.