Codechange: Move Sound Driver parameter name listings

[krysclarke]

Motivation / Problem

The various sound drivers don't take a consistent set of (optional) parameters, which could cause confusion if someone was trying to change the audio settings and wondering why nothing was actually changing.

Description

This change places the list of accepted parameters for each sound driver on the line in the openttd --help to be with the individual sound drivers, rather than at the top.

i.e.:

From:
-s drv = Set sound driver (see below) (param bufsize,hz)
...
List of sound drivers:
sdl: SDL Sound Driver
null: Null Sound Driver

To:
-s drv = Set sound driver (see below)
...
List of sound drivers:
sdl: SDL Sound Driver (param hz,samples)
null: Null Sound Driver

Limitations

None known.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR touches english.txt or translations? Check the guidelines
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker