drm/i915/dp: Return early if getting/acking device service IRQs fails

drm/i915/dp: Return early if getting/acking device service IRQs fails

If getting/acking the device service IRQs fail, the short HPD handler
should bail out, falling back to a full connector detection as in case
of any AUX access failures during the HPD handling. Do this by
separating the getting/acking and handling steps of the IRQs.

Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-14-imre.deak@intel.com