drm/i915/display: convert vlv_wait_port_ready() to struct intel_display

drm/i915/display: convert vlv_wait_port_ready() to struct intel_display

struct intel_display will replace struct drm_i915_private as the main
device pointer for display code. Switch vlv_wait_port_ready() over to
it. The main motivation to do just one function is to stop passing i915
to intel_de_wait(), so its generic wrapper can be removed.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9505ea49dfc8c7a52cacd2749875a680b01e5bbd.1730146000.git.jani.nikula@intel.com