boards: st: nucleo_wba65ri: update arduino spi node

According to user manual UM3448, spi2 is connected to
the ST Arduino header.

This has been confirmed using the spi_loopback test driver.

Also update documentation.

Signed-off-by: Fabrice DJIATSA <fabrice.djiatsa-ext@st.com>

boards/st/nucleo_wba65ri/arduino_r3_connector.dtsi

@@ -36,4 +36,4 @@
 };
 
 arduino_i2c: &i2c1 {};
-arduino_spi: &spi1 {};
+arduino_spi: &spi2 {};

boards/st/nucleo_wba65ri/doc/nucleo_wba65ri.rst

@@ -168,10 +168,10 @@ Default Zephyr Peripheral Mapping:
 - I2C_1_SDA : PB1
 - USER_PB : PC13
 - LD1 : PD8
-- SPI_1_NSS : PA12 (arduino_spi)
-- SPI_1_SCK : PB4 (arduino_spi)
-- SPI_1_MISO : PB3 (arduino_spi)
-- SPI_1_MOSI : PA15 (arduino_spi)
+- SPI_2_NSS : PB9 (arduino_spi)
+- SPI_2_SCK : PB10 (arduino_spi)
+- SPI_2_MISO : PA9 (arduino_spi)
+- SPI_2_MOSI : PC3 (arduino_spi)
 
 System Clock
 ------------

boards/st/nucleo_wba65ri/nucleo_wba65ri.dts

@@ -123,9 +123,9 @@
 	status = "okay";
 };
 
-&spi1 {
-	pinctrl-0 = <&spi1_nss_pa12 &spi1_sck_pb4
-		     &spi1_miso_pb3 &spi1_mosi_pa15>;
+&spi2 {
+	pinctrl-0 = <&spi2_nss_pb9 &spi2_sck_pb10
+		     &spi2_miso_pa9 &spi2_mosi_pc3>;
 	pinctrl-names = "default";
 	status = "okay";
 };