boards: arm: atmel: Add flash support to SAM0 xpro boards

Add the following XPRO boards to flash driver test:
SAMD20, SAMDE54 and SAMR21

Signed-off-by: Daniel Evans <photonthunder@gmail.com>

Co-authored-by: Gerson Fernando Budke nandojve@gmail.com

boards/arm/atsamd20_xpro/atsamd20_xpro.yaml

@@ -10,6 +10,7 @@ toolchain:
   - xtools
 supported:
   - adc
+  - flash
   - gpio
   - i2c
   - spi

boards/arm/atsame54_xpro/atsame54_xpro.dts

@@ -138,3 +138,21 @@ zephyr_udc0: &usb0 {
 		reg = <0>;
 	};
 };
+
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/*
+		 * The final 16 KiB is reserved for the application.
+		 * Storage partition will be used by FCB/LittleFS/NVS
+		 * if enabled.
+		 */
+		storage_partition: partition@fc000 {
+			label = "storage";
+			reg = <0x000fc000 0x00004000>;
+		};
+	};
+};

boards/arm/atsame54_xpro/atsame54_xpro.yaml

@@ -12,6 +12,7 @@ toolchain:
   - xtools
 supported:
   - adc
+  - flash
   - gpio
   - pwm
   - spi

boards/arm/atsamr21_xpro/atsamr21_xpro.dts

@@ -207,3 +207,21 @@ ext2_spi: &sercom5 {
 
 ext2_i2c: &sercom1 {
 };
+
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/*
+		 * The final 16 KiB is reserved for the application.
+		 * Storage partition will be used by FCB/LittleFS/NVS
+		 * if enabled.
+		 */
+		storage_partition: partition@3c000 {
+			label = "storage";
+			reg = <0x0003c000 0x00004000>;
+		};
+	};
+};

boards/arm/atsamr21_xpro/atsamr21_xpro.yaml

@@ -13,6 +13,7 @@ toolchain:
   - xtools
 supported:
   - adc
+  - flash
   - gpio
   - i2c
   - netif

tests/drivers/flash/common/testcase.yaml

@@ -83,3 +83,8 @@ tests:
     extra_args:
       - OVERLAY_CONFIG=boards/nrf52840dk_flash_spi.conf
       - DTC_OVERLAY_FILE=boards/nrf52840dk_spi_nor_wp_hold.overlay
+  drivers.flash.common.sam0:
+    platform_allow:
+      - atsamd20_xpro
+      - atsamr21_xpro
+      - atsame54_xpro