drm/i915/hsw: Rename the get HDMI/DP DPLL funcs to get WRPLL/LCPLL

The types of PLLs used for HDMI/DP on HSW are WRPLL/LCPLL accordingly,
so use these names to align better with the rest of WRPLL/LCPLL function
names elsewhere.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226203455.23032-9-imre.deak@intel.com