tools/rtla: Move top/hist params into common struct

The hist members were very similar between timerlat and top, so
just use one common hist struct.

output_divisor, quiet, and pretty printing are pretty generic
concepts that can go in the main struct even if not every
specific tool (currently) uses them.

Cc: John Kacur <jkacur@redhat.com>
Cc: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/20250907022325.243930-3-crwood@redhat.com


Reviewed-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Crystal Wood <crwood@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>