drm/i915/hdcp: Use correct cp_irq_count

drm/i915/hdcp: Use correct cp_irq_count

We are checking cp_irq_count from the wrong hdcp structure which
ends up giving timed out errors. We only increment the cp_irq_count
of the primary connector's hdcp structure but here in case of
multidisplay setup we end up checking the secondary connector's hdcp
structure, which will not have its cp_irq_count incremented. This leads
to a timed out at CP_IRQ error even though a CP_IRQ was raised. Extract
it from the correct intel_hdcp structure.

--v2
-Explain why it was the wrong hdcp structure [Jani]

Fixes: 8c9e4f68b861 ("drm/i915/hdcp: Use per-device debugs")
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240809114127.3940699-2-suraj.kandpal@intel.com
(cherry picked from commit dd925902634def895690426bf10e0a8b3e56f56d)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>