drm/i915/dsi: Fix NULL pointer deref in vlv_dphy_param_init()

drm/i915/dsi: Fix NULL pointer deref in vlv_dphy_param_init()

Commit 77ba0b856225 ("drm/i915/dsi: convert vlv_dsi.[ch] to struct
intel_display") added a to_intel_display(connector) call to
vlv_dphy_param_init() but when vlv_dphy_param_init() gets called
the connector object has not been initialized yet, so this leads
to a NULL pointer deref:

 BUG: kernel NULL pointer dereference, address: 000000000000000c
 ...
 Hardware name: ASUSTeK COMPUTER INC. T100TA/T100TA, BIOS T100TA.314 08/13/2015
 RIP: 0010:vlv_dsi_init+0x4e6/0x1600 [i915]
 ...
 Call Trace:
  <TASK>
  ? intel_step_name+0x4be8/0x5c30 [i915]
  intel_setup_outputs+0x2d6/0xbd0 [i915]
  intel_display_driver_probe_nogem+0x13f/0x220 [i915]
  i915_driver_probe+0x3d9/0xaf0 [i915]

Use to_intel_display(&intel_dsi->base) instead to fix this.

Fixes: 77ba0b856225 ("drm/i915/dsi: convert vlv_dsi.[ch] to struct intel_display")
Signed-off-by: Hans de Goede <hansg@kernel.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://lore.kernel.org/r/20250626143317.101706-1-hansg@kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 0dc6bfb50a5d0759e726cd36a3d3b7529fd2a627)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>