drm/i915/ehl: inherit icl cdclk init/uninit

The cdclk init/uninit code was changed by commit 93a643f2
("drm/i915/cdclk: have only one init/uninit function") between the
versions of commit 39564ae8 ("drm/i915/ehl: Inherit Ice Lake
conditional code"). What got merged fails to do cdclk init/uninit on
ehl.

Fixes: 39564ae8 ("drm/i915/ehl: Inherit Ice Lake conditional code")
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190416082852.18141-1-jani.nikula@intel.com