drm/i915/skl: Adding DDI_E power well domain

From B spec, DDI_E port belong to PowerWell 2, but
DDI_E share the powerwell_req/staus register bit with
DDI_A which belong to DDI_A_E_POWER_WELL.

In order to communicate with the connector on DDI-E, both
DDI_A_E_POWER_WELL and POWER_WELL_2 must be enabled.

Currently intel_dp_power_get(DDI_E) only enable
DDI_A_E_POWER_WELL, this patch will not only enable
DDI_a_E_POWER_WELL but also enable POWER_WELL_2.

This patch also fix the DDI-E hotplug function.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9bae133..a5cddcd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5150,7 +5150,6 @@
 {
 	switch (port) {
 	case PORT_A:
-	case PORT_E:
 		return POWER_DOMAIN_PORT_DDI_A_4_LANES;
 	case PORT_B:
 		return POWER_DOMAIN_PORT_DDI_B_4_LANES;
@@ -5158,6 +5157,8 @@
 		return POWER_DOMAIN_PORT_DDI_C_4_LANES;
 	case PORT_D:
 		return POWER_DOMAIN_PORT_DDI_D_4_LANES;
+	case PORT_E:
+		return POWER_DOMAIN_PORT_DDI_E_2_LANES;
 	default:
 		WARN_ON_ONCE(1);
 		return POWER_DOMAIN_PORT_OTHER;