tools/rtla: Add common_usage()

tools/rtla: Add common_usage()

The rtla tools have significant code quadruplication in their usage
functions. Each tool implements its own version of the same help text
formatting and option descriptions, leading to maintenance overhead and
inconsistencies.  Documentation/tools/rtla/common_options.rst lists 14
common options.

Add common_usage() infrastructure to consolidate help formatting.
Subsequent patches will extend this to handle other common options.

The refactored output is almost identical to the original, with the
following changes:
- add square brackets to specify optionality: `usage: [rtla] ...`
- remove `-q` from timerlat hist because hist tools don't support it
- minor spacing

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/r/20251124063204.845425-1-costa.shul@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>