dts: cadence_spi: Sync DT bindings with Linux

Adopt the Linux DT bindings and clean-up duplicate
and unused values.

Fix indentation of the QSPI node in the keystone k2g
device tree.

Tested on TI K2G platform:
Tested-by: Vignesh R <vigneshr@ti.com>

Tested on a socfpga-cyclonev board:
Tested-by: Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>

Signed-off-by: Jason Rush <jarush@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Acked-by: Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/arch/arm/dts/socfpga_cyclone5_socdk.dts b/arch/arm/dts/socfpga_cyclone5_socdk.dts
index f175ef2..95a8e65 100644
--- a/arch/arm/dts/socfpga_cyclone5_socdk.dts
+++ b/arch/arm/dts/socfpga_cyclone5_socdk.dts
@@ -104,11 +104,10 @@
 		m25p,fast-read;
 		page-size = <256>;
 		block-size = <16>; /* 2^16, 64KB */
-		read-delay = <4>;  /* delay value in read data capture register */
-		tshsl-ns = <50>;
-		tsd2d-ns = <50>;
-		tchsh-ns = <4>;
-		tslch-ns = <4>;
+		cdns,tshsl-ns = <50>;
+		cdns,tsd2d-ns = <50>;
+		cdns,tchsh-ns = <4>;
+		cdns,tslch-ns = <4>;
 	};
 };