drm/i915/icp+: Use icp_hpd_irq_setup() instead of spt_hpd_irq_setup()

While reviewing patches for handling workarounds related to gen9 bc, Imre
from Intel discovered that we're using spt_hpd_irq_setup() on ICP+ PCHs
despite it being almost the same as icp_hpd_irq_setup(). Since we need to
be calling icp_hpd_irq_setup() to ensure that CML-S/TGP platforms function
correctly anyway, let's move platforms using PCH_ICP which aren't handled
by gen11_hpd_irq_setup() over to icp_hpd_irq_setup().

Cc: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210217025337.1929015-2-lyude@redhat.com