ARM: dts: stm32: Fix SPI controller node names

SPI controller nodes should be named 'spi' rather than 'qspi'. Fixing the
name enables dtc SPI bus checks.

Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp157c.dtsi

@@ -947,7 +947,7 @@ mdma1: dma@58000000 {
 			dma-requests = <48>;
 		};
 
-		qspi: qspi@58003000 {
+		qspi: spi@58003000 {
 			compatible = "st,stm32f469-qspi";
 			reg = <0x58003000 0x1000>, <0x70000000 0x10000000>;
 			reg-names = "qspi", "qspi_mm";