drm/msm/hdmi: add "qcom,hdmi-tx-8998" compatible

Current driver already supports the msm8998 HDMI TX.
We just need to add the compatible string.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Marc Gonzalez <mgonzalez@freebox.fr>
Patchwork: https://patchwork.freedesktop.org/patch/605632/
Link: https://lore.kernel.org/r/20240724-hdmi-tx-v7-3-e44a20553464@freebox.frSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/hdmi/hdmi.c

@@ -549,6 +549,7 @@ static void msm_hdmi_dev_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id msm_hdmi_dt_match[] = {
+	{ .compatible = "qcom,hdmi-tx-8998", .data = &hdmi_tx_8974_config },
 	{ .compatible = "qcom,hdmi-tx-8996", .data = &hdmi_tx_8974_config },
 	{ .compatible = "qcom,hdmi-tx-8994", .data = &hdmi_tx_8974_config },
 	{ .compatible = "qcom,hdmi-tx-8084", .data = &hdmi_tx_8974_config },