boot: zephyr: add ram_load overlays for nrf52840dk and mimxrt1050_evk boards

Add ram load overlays for nrf52840dk and mimxrt1050_evk boards. These
ram load overlays are moved from the Zephyr in tree smp_svr sample, to
enable ram load support for multiple platforms.

Signed-off-by: Daniel DeGrasse <ddegrasse@tenstorrent.com>

Author: danieldegrasse

boot/zephyr/boards/mimxrt1050_evk_mimxrt1052_hyperflash_ram_load.overlay

@@ -0,0 +1,31 @@
+/ {
+	sram@80007F00 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x80007F00 0x100>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+
+		retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			boot_info0: boot_info@0 {
+				compatible = "zephyr,retention";
+				status = "okay";
+				reg = <0x0 0x100>;
+			};
+		};
+	};
+
+	chosen {
+		zephyr,bootloader-info = &boot_info0;
+		zephyr,code-partition = &boot_partition;
+	};
+};
+
+/* Reduce size of slot 0 to match slot 1 */
+&slot0_partition {
+	reg = <0x40000 0x300000>;
+};

boot/zephyr/boards/nrf52840dk_nrf52840_ram_load.overlay

@@ -0,0 +1,31 @@
+&gpregret1 {
+	/delete-node/ boot_mode@0;
+};
+
+/ {
+	sram@2003FC00 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x2003FC00 DT_SIZE_K(1)>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+
+		retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			boot_info0: boot_info@0 {
+				compatible = "zephyr,retention";
+				status = "okay";
+				reg = <0x0 0x100>;
+			};
+		};
+	};
+
+	chosen {
+		/delete-property/ zephyr,boot-mode;
+		zephyr,bootloader-info = &boot_info0;
+		zephyr,code-partition = &boot_partition;
+	};
+};