[nrf noup] zephyr: sysflash: Fix undefined TARGET_NAME in dependency

The add_dependencies() call introduced together with the
PCD_NET_CORE_APP_ADDRESS / PCD_NET_CORE_APP_SIZE compile definitions
used ${TARGET_NAME}, which is not defined anywhere in MCUboot's CMake
or Kconfig. CMake therefore expanded it to an empty string and aborted
the configure step with:

    add_dependencies called with incorrect number of arguments

This affected every build enabling the new code path, that is:

    CONFIG_PARTITION_MANAGER_ENABLED=n
    CONFIG_SOC_NRF5340_CPUAPP=y
    CONFIG_MCUBOOT_NETWORK_CORE_IMAGE_NUMBER set (multi-image update)

Replaced ${TARGET_NAME} with the standard Zephyr application library
target name app, matching how add_dependencies() is used elsewhere
across the tree.

Signed-off-by: Kamil Piszczek <Kamil.Piszczek@nordicsemi.no>

Author: kapi-no

boot/zephyr/CMakeLists.txt

@@ -849,7 +849,7 @@ if(NOT CONFIG_PARTITION_MANAGER_ENABLED AND CONFIG_SOC_NRF5340_CPUAPP)
     # Really this dependency if set for MCUboot, but it will also cover s1 image,
     # since contition that let us here checks for `CONFIG_MCUBOOT` which is only
     # set for MCUboot builds.
-    add_dependencies(${TARGET_NAME} b0n_target)
+    add_dependencies(app b0n_target)
 
     dt_nodelabel(s0_partition_path NODELABEL s0_partition REQUIRED TARGET b0n_target)
     dt_reg_addr(s0_partition_address PATH ${s0_partition_path} TARGET b0n_target)