drm/msm/dsi: Uncomment core_mmss clock for MSM8996

The MSM8996 core_mmss clock was commented out due to some
strange issues that others were experiencing.

At least SONY Tone family is working perfectly fine with this clock
declared and gets it up and running without any error.

Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
Signed-off-by: Konrad Dybcio <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/dsi/dsi_cfg.c

···
 	.num_dsi = 2,
 };
 
-/*
- * TODO: core_mmss_clk fails to enable for some reason, but things work fine
- * without it too. Figure out why it doesn't enable and uncomment below
- */
 static const char * const dsi_8996_bus_clk_names[] = {
-	"mdp_core", "iface", "bus", /* "core_mmss", */
+	"mdp_core", "iface", "bus", "core_mmss",
 };
 
 static const struct msm_dsi_config msm8996_dsi_cfg = {