drm/radeon: Do not hold console lock during resume

The function radeon_resume_kms() acquires the console lock. It is
inconsistent, as it depends on the notify_client argument. That
lock then covers a number of suspend operations that are unrelated
to the console.

Remove the calls to console_lock() and console_unlock() from the
radeon function. The console lock is only required by DRM's fbdev
emulation, which acquires it as necessary.

Also fixes a possible circular dependency between the console lock
and the client-list mutex, where the mutex is supposed to be taken
first.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>