drivers: spi: Add support for Apollo3 SoCs SPI

This commit adds support for the SPI which
can be found in Apollo3 SoCs, it can work in
both DMA and non-DMA modes

Signed-off-by: Hao Luo <hluo@ambiq.com>

boards/ambiq/apollo3_evb/apollo3_evb.dts

@@ -101,6 +101,14 @@
 	status = "okay";
 };
 
+&spi0 {
+	compatible = "ambiq,spi";
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-names = "default";
+	clock-frequency = <DT_FREQ_M(1)>;
+	status = "okay";
+};
+
 &i2c3 {
 	compatible = "ambiq,i2c";
 	pinctrl-0 = <&i2c3_default>;

boards/ambiq/apollo3_evb/apollo3_evb.yaml

@@ -12,6 +12,7 @@ supported:
   - watchdog
   - counter
   - gpio
+  - spi
   - i2c
 testing:
   ignore_tags:

boards/ambiq/apollo3p_evb/apollo3p_evb.dts

@@ -101,6 +101,14 @@
 	status = "okay";
 };
 
+&spi0 {
+	compatible = "ambiq,spi";
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-names = "default";
+	clock-frequency = <DT_FREQ_M(1)>;
+	status = "okay";
+};
+
 &i2c3 {
 	compatible = "ambiq,i2c";
 	pinctrl-0 = <&i2c3_default>;

boards/ambiq/apollo3p_evb/apollo3p_evb.yaml

@@ -12,6 +12,7 @@ supported:
   - watchdog
   - counter
   - gpio
+  - spi
   - i2c
 testing:
   ignore_tags: