ARM: dts: stm32: Configure qspi's mdma transfer to block for stm32mp151

Configure qspi's mdma from buffer transfer (max 128 bytes) to
block transfer (max 64K bytes).

mtd_speedtest shows that write throughtput increases :
  - from 734 to 782 KiB/s (~6.5%) with s25fl512s SPI-NOR.
  - from 4848 to 5319 KiB/s (~9.72%) with Micron SPI-NAND.
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/stm32mp151.dtsi

@@ -1369,8 +1369,8 @@ qspi: spi@58003000 {
 			reg = <0x58003000 0x1000>, <0x70000000 0x10000000>;
 			reg-names = "qspi", "qspi_mm";
 			interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>;
-			dmas = <&mdma1 22 0x2 0x100002 0x0 0x0>,
-			       <&mdma1 22 0x2 0x100008 0x0 0x0>;
+			dmas = <&mdma1 22 0x2 0x10100002 0x0 0x0>,
+			       <&mdma1 22 0x2 0x10100008 0x0 0x0>;
 			dma-names = "tx", "rx";
 			clocks = <&rcc QSPI_K>;
 			resets = <&rcc QSPI_R>;