drm/log: Implement suspend/resume

Normally the console is already suspended when the graphic driver
suspend callback is called, but if the parameter no_console_suspend
is set, it might still be active.
So call console_stop()/console_start() in the suspend/resume
callbacks, to make sure it won't try to write to the framebuffer
while the graphic driver is suspended.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241204160014.1171469-6-jfalempe@redhat.com