We want sometimes to keep the runtime PM disabled persistently just
like we did for the PM deny-list in the previous change, e.g. for
testing some buggy device.  This patch enhances the existing
pm_blacklist option for achieving it easily.

The default behavior doesn't change -- the driver looks up the deny
list and disables the runtime PM if matches.  However, when
pm_blacklist=1 option is set, now the driver disables the runtime PM
completely, just like the deny-list does.

Update the documentation for this option, too.

Link: https://patch.msgid.link/20240729141519.18398-2-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>