drm/i915/hdcp: Move aux assignment after connector type check

Move assignment of aux after connector type check as port may not
exist if connector is not DPMST.

--v2
-Fix unwanted change in intel_encoder check [Jani]

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240521081458.1500327-2-suraj.kandpal@intel.com