drm/i915: Reuse pipe_config_mismatch() more

Just call pipe_config_mismatch() from all the more specialized
mismatch() functions instead of hand rolling the same printfs
all over.

v2: Eliminate the dpll drm_debug_enabled() in an earlier patch (Jani)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240229184207.31233-1-ville.syrjala@linux.intel.com