drm/i915/tgl: Return the mg/dkl pll as DDI clock for new TC ports

TGL added 2 more TC ports that currently are not being handled by
icl_pll_to_ddi_clk_sel(), so adding those.
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reported-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190924210040.142075-6-jose.souza@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -1049,6 +1049,8 @@ static u32 icl_pll_to_ddi_clk_sel(struct intel_encoder *encoder,
 	case DPLL_ID_ICL_MGPLL2:
 	case DPLL_ID_ICL_MGPLL3:
 	case DPLL_ID_ICL_MGPLL4:
+	case DPLL_ID_TGL_MGPLL5:
+	case DPLL_ID_TGL_MGPLL6:
 		return DDI_CLK_SEL_MG;
 	}
 }