drm/i915: s/dev_priv/i915/ for the remainder of DDI clock routing

Convert the remaining 'dev_priv's to 'i915's in the DDI
clock routing functions.

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210205214634.19341-16-ville.syrjala@linux.intel.com


Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>