hw_pal_timer, hw_pal_timer_value): Define.
(hw_pal_io_read_buffer, hw_pal_io_write_buffer): Add timer support
(do_counter_event, do_counter_read, do_counter_value,
do_counter_write): new functions.
* hw-tree.c (hw_printf): Send tree dump to stderr, same as other
trace output.
* hw-base.c (hw_create): Stop searching for a device when one is
found.