drm/i915/skl: Don't try to store the wrong central frequency

The orignal code started by storing the actual central frequency (in Hz,
using a uint64_t) in a uint32_t which codes for the register value. That
can't be right.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_ddi.c

@@ -1121,8 +1121,6 @@ static void skl_wrpll_params_populate(struct skl_wrpll_params *params,
 {
 	uint64_t dco_freq;
 
-	params->central_freq = central_freq;
-
 	switch (central_freq) {
 	case 9600000000ULL:
 		params->central_freq = 0;