drm/i915/hdcp: Extract hdcp structure from correct connector

Currently intel_hdcp is not being extracted from primary connector
this patch fixes that.

Fixes: 524240b2 ("drm/i915/hdcp: Propagate aux info in DP HDCP functions")
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240226063051.1685326-3-suraj.kandpal@intel.com