drm/i915/mtl: MTL PICA hotplug detection

PICA is used for DP alt mode and TBT modes. Hotplug interruption is routed
from PICA chip to south display engine and from there to north display
engine. This patch adds functionality to enable hotplug detection for
all Type-C ports (4 ports available).

Differently from HPD in south display, PICA provides a dedicated HPD
control register for each supported port, so we loop over ports
ourselves instead of using intel_hpd_hotplug_enables() or
intel_get_hpd_pins().

BSpec: 49305, 55726, 65107, 65300

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Madhumitha Tolakanahalli Pradeep <madhumitha.tolakanahalli.pradeep@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413212443.1504245-6-radhakrishna.sripada@intel.com