ARM: dts: stm32: Fix qspi memory map size for stm32f7 boards

stm32f746-disco embeds a 16Mb qspi flash, stm32f746-eval and
stm32f769-disco embeds a 64Mb qspi flash.
Update the reg property accordingly

Remove deprecated memory-map property.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32f769-disco-u-boot.dtsi b/arch/arm/dts/stm32f769-disco-u-boot.dtsi
index e9e43cb..96770da 100644
--- a/arch/arm/dts/stm32f769-disco-u-boot.dtsi
+++ b/arch/arm/dts/stm32f769-disco-u-boot.dtsi
@@ -155,6 +155,7 @@
 };
 
 &qspi {
+	reg = <0xA0001000 0x1000>, <0x90000000 0x4000000>;
 	flash0: mx66l51235l {
 		#address-cells = <1>;
 		#size-cells = <1>;