xilinx: Fix xlnx,mio_bank property

s/xlnx,mio_bank/xlnx,mio-bank/g

DT binding is describing mio-bank not mio_bank that's why fix all DTSes and
also driver itself.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Peng Fan <peng.fan@nxp.com>

diff --git a/arch/arm/dts/avnet-ultrazedev-cc-v1.0-ultrazedev-som-v1.0.dts b/arch/arm/dts/avnet-ultrazedev-cc-v1.0-ultrazedev-som-v1.0.dts
index ac641ff..85ab9e9 100644
--- a/arch/arm/dts/avnet-ultrazedev-cc-v1.0-ultrazedev-som-v1.0.dts
+++ b/arch/arm/dts/avnet-ultrazedev-cc-v1.0-ultrazedev-som-v1.0.dts
@@ -51,7 +51,7 @@
 /* microSD card slot */
 &sdhci1 {
 	status = "okay";
-	xlnx,mio_bank = <1>;
+	xlnx,mio-bank = <1>;
 	clock-frequency = <199998000>;
 	max-frequency = <50000000>;
 	no-1-8-v;