ARM: dts: dra7x: Support QSPI MODE-0 operation at 64MHz

According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on
DRA74(rev 1.1+)/DRA72 EVM can support up to 64MHz in MODE-0, whereas
MODE-3 is limited to 48MHz. Hence, switch to MODE-0 for better
throughput.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>

arch/arm/dts/dra7-evm.dts

@@ -491,15 +491,13 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&qspi1_pins>;
 
-	spi-max-frequency = <48000000>;
+	spi-max-frequency = <64000000>;
 	m25p80@0 {
 		compatible = "s25fl256s1","spi-flash";
-		spi-max-frequency = <48000000>;
+		spi-max-frequency = <64000000>;
 		reg = <0>;
 		spi-tx-bus-width = <1>;
 		spi-rx-bus-width = <4>;
-		spi-cpol;
-		spi-cpha;
 		#address-cells = <1>;
 		#size-cells = <1>;
 

arch/arm/dts/dra72-evm.dts

@@ -603,15 +603,13 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&qspi1_pins>;
 
-	spi-max-frequency = <48000000>;
+	spi-max-frequency = <64000000>;
 	m25p80@0 {
 		compatible = "s25fl256s1","spi-flash";
-		spi-max-frequency = <48000000>;
+		spi-max-frequency = <64000000>;
 		reg = <0>;
 		spi-tx-bus-width = <1>;
 		spi-rx-bus-width = <4>;
-		spi-cpol;
-		spi-cpha;
 		#address-cells = <1>;
 		#size-cells = <1>;