drm/i915/hdcp: Drop mgr->base.lock acquisition in intel_conn_to_vcpi()

drm/i915/hdcp: Drop mgr->base.lock acquisition in intel_conn_to_vcpi()

Now that intel_conn_to_vcpi() reads the MST topology state via
drm_atomic_get_new_mst_topology_state(), the topology state belongs
to this atomic commit and is already serialized through the atomic
state's private object machinery. There is no need to additionally
take mgr->base.lock here.
Taking it from the HDCP enable path in commit_tail with
state->base.acquire_ctx is also unsafe: by this point the
acquire_ctx is no longer in a state where new modeset locks may be
acquired through it, which produces a modeset-lock splat on MST +
HDCP. Drop the drm_modeset_lock() call.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Tested-by: Santhosh Reddy Guddati <santhosh.reddy.guddati@intel.com>
Reviewed-by: Santhosh Reddy Guddati <santhosh.reddy.guddati@intel.com>
Link: https://patch.msgid.link/20260504101117.3619984-3-suraj.kandpal@intel.com