drm/i915/dpll: drop a useless I915_STATE_WARN_ON()

In general, we don't do assertions that a function gets called on the
right platforms, and if we did, it should not be a state warn.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512110444.1448231-1-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_dpll_mgr.c

@@ -464,8 +464,6 @@ static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
 	u32 val;
 	bool enabled;
 
-	I915_STATE_WARN_ON(!(HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv)));
-
 	val = intel_de_read(dev_priv, PCH_DREF_CONTROL);
 	enabled = !!(val & (DREF_SSC_SOURCE_MASK | DREF_NONSPREAD_SOURCE_MASK |
 			    DREF_SUPERSPREAD_SOURCE_MASK));