[nrf noup] boards: thingy53_nrf5340: Enable MCUboot by default

Change enables MCUboot bootloader by default to allow programming
samples and applications without external programmer (using MCUboot
serial recovery). Change also enables network core to prevent build
failures when building MCUboot with nRF53 multi image DFU.

Jira: NCSDK-18263

Signed-off-by: Marek Pieta <[email protected]>
Signed-off-by: Vinayak Kariappa Chettimada <[email protected]>
Signed-off-by: Johann Fischer <[email protected]>
Signed-off-by: Joakim Andersson <[email protected]>
(cherry picked from commit ce70796)

Author: MarekPieta

boards/nordic/thingy53/Kconfig.defconfig

@@ -8,6 +8,12 @@ config HW_STACK_PROTECTION
 
 if BOARD_THINGY53_NRF5340_CPUAPP || BOARD_THINGY53_NRF5340_CPUAPP_NS
 
+config BOOTLOADER_MCUBOOT
+	default y if !MCUBOOT
+
+config BOARD_ENABLE_CPUNET
+	default y if !MCUBOOT
+
 # Code Partition:
 #
 # For the secure version of the board the firmware is linked at the beginning

boards/nordic/thingy53/thingy53_nrf5340_common.dtsi

@@ -13,6 +13,7 @@
 		zephyr,bt-hci = &bt_hci_ipc0;
 		nordic,802154-spinel-ipc = &ipc0;
 		zephyr,ieee802154 = &ieee802154;
+		nordic,pm-ext-flash = &mx25r64;
 	};
 
 	buttons {