drm/nouveau/bios/init: drop kernel-doc notation

The "/**" comments in this file are not kernel-doc comments. They are
used on static functions which can have kernel-doc comments, but that
is not the primary focus of kernel-doc comments.
Since these comments are incomplete for kernel-doc notation, remove
the kernel-doc "/**" markers and make them common comments.

This prevents scripts/kernel-doc from issuing 68 warnings:

init.c:584: warning: Function parameter or member 'init' not described in 'init_reserved'

and 67 warnings like this one:
init.c:611: warning: expecting prototype for INIT_DONE(). Prototype was for init_done() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231216201152.31376-1-rdunlap@infradead.org