drm/i915/dsi: Print the VBT MIPI sequence delay duration

Help out debugging things by printing out how long the VBT
delay sequence is supposed to wait.

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/20230608203057.23759-4-ville.syrjala@linux.intel.com