stm32f7: use clock driver to enable qspi controller clock

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
cc: Christophe KERELLO <christophe.kerello@st.com>
diff --git a/arch/arm/dts/stm32f746.dtsi b/arch/arm/dts/stm32f746.dtsi
index b2b0b5f..883f818 100644
--- a/arch/arm/dts/stm32f746.dtsi
+++ b/arch/arm/dts/stm32f746.dtsi
@@ -78,6 +78,7 @@
 			reg-names = "QuadSPI", "QuadSPI-memory";
 			interrupts = <92>;
 			spi-max-frequency = <108000000>;
+			clocks = <&rcc 0 65>;
 			status = "disabled";
 		};
 		usart1: serial@40011000 {