intel_extreme: disable CK505 clock source

Using the CK505 clock source may need some more checks or configuration
we currently don't do, leading to a blank screen in some systems.
Whatever the reason, disabling it makes the driver work on my machine.

Fixes #16357

Change-Id: If207ffdddcf6e6eb73bc69ce5a8bd2842fd2141b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3867
Reviewed-by: Adrien Destugues <[email protected]>

src/add-ons/accelerants/intel_extreme/pll.cpp

@@ -481,7 +481,7 @@ refclk_activate_ilk(bool hasPanel)
 	bool hasCK505;
 	if (gInfo->shared_info->pch_info == INTEL_PCH_IBX) {
 		//XXX: This should be == vbt display_clock_mode
-		hasCK505 = true;
+		hasCK505 = false;
 		wantsSSC = hasCK505;
 	} else {
 		hasCK505 = false;