drm/i915: Extend icl_sanitize_encoder_pll_mapping() to all DDI platforms

drm/i915: Extend icl_sanitize_encoder_pll_mapping() to all DDI platforms

Now that all the encoder clock stuff is uniformly abstracted
for all hsw+ platforms, let's extend icl_sanitize_encoder_pll_mapping()
to cover all of them.

Not sure there is a particular benefit in doing so, but less special
cases always makes me happy.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210224144214.24803-7-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>