mmc: dt: Consolidate DT bindings

This patch unifies the current DT MMC bindings documentation and code,
adds generic MMC DT bindings documentation, and updates .dts files for
consistency.

[cjb: typo fixes, addition of max-frequency property]
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/boot/dts/imx53-smd.dts b/arch/arm/boot/dts/imx53-smd.dts
index c7ee86c..139138a 100644
--- a/arch/arm/boot/dts/imx53-smd.dts
+++ b/arch/arm/boot/dts/imx53-smd.dts
@@ -35,7 +35,7 @@
 				};
 
 				esdhc@50008000 { /* ESDHC2 */
-					fsl,card-wired;
+					non-removable;
 					status = "okay";
 				};
 
@@ -76,7 +76,7 @@
 				};
 
 				esdhc@50020000 { /* ESDHC3 */
-					fsl,card-wired;
+					non-removable;
 					status = "okay";
 				};
 			};