RFC: better timer interface

[Christoph Hellwig]

Hi all,

this series attempts to provide a "modern" timer interface where the
callback gets the timer_list structure as an argument so that it
can use container_of instead of having to cast to/from unsigned long
all the time (or even worse use function pointer casts, we have quite
a few of those as well).

For that it steals another bit from the cpu mask to add a modern flag,
and if that flag is set the different new function prototype is used.
Last but least new helpers to initialize these modern timers are added.
Instead of having a larger number of initialization macros we simply
pass the timer flags to them.