drm/i915/dsi: Make 'clock_stop' boolean

drm/i915/dsi: Make 'clock_stop' boolean

The DSI 'clock_stop' parameter is a boolean, so use a real
'bool' for it. And pimp the debug print while at it.

Note that we also remove the incorrect negation of the value
in the debug print. That has been there since the code was
introduced in commit 2ab8b458c6a1 ("drm/i915: Add support for
Generic MIPI panel driver"). An earlier version of the patch
https://lore.kernel.org/intel-gfx/1397454507-10273-5-git-send-email-shobhit.kumar@intel.com/
got it right, but looks like it got fumbled while dealing
with other review comments.

v2: Highlight the removal of the '!' (Jani)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260326111814.9800-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>