drm/i915/icl+: Fix hotplug interrupt disabling after storm detection

Atm, hotplug interrupts on TypeC ports are left enabled after detecting
an interrupt storm, fix this.
Reported-by: Kunal Joshi <kunal1.joshi@intel.com>
References: https://gitlab.freedesktop.org/drm/intel/-/issues/351
Bugzilla: https://gitlab.freedesktop.org/drm/intel/-/issues/1964
Cc: Kunal Joshi <kunal1.joshi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200612121731.19596-1-imre.deak@intel.com
(cherry picked from commit 587a87b9)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_irq.c

@@ -3125,6 +3125,7 @@ static void gen11_hpd_irq_setup(struct drm_i915_private *dev_priv)
 
 	val = I915_READ(GEN11_DE_HPD_IMR);
 	val &= ~hotplug_irqs;
+	val |= ~enabled_irqs & hotplug_irqs;
 	I915_WRITE(GEN11_DE_HPD_IMR, val);
 	POSTING_READ(GEN11_DE_HPD_IMR);