dt-bindings: mmc: Add disable-cqe-dcmd property.

Add disable-cqe-dcmd as optional property for MMC hosts.
This property allows to disable or not enable the direct command
features of the command queue engine.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Fixes: 84362d7 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: cmuellner

Documentation/devicetree/bindings/mmc/mmc.txt

@@ -64,6 +64,8 @@ Optional properties:
   whether pwrseq-simple is used. Default to 10ms if no available.
 - supports-cqe : The presence of this property indicates that the corresponding
   MMC host controller supports HW command queue feature.
+- disable-cqe-dcmd: This property indicates that the MMC controller's command
+  queue engine (CQE) does not support direct commands (DCMDs).
 
 *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
 polarity properties, we have to fix the meaning of the "normal" and "inverted"