samples: tfm_ipc: add test-variant for TF-M without BL2
samples: tfm_ipc: add test-variant for TF-M without BL2

We add a test variant in tfm_ipc test, to validate the
scenario where TF-M is built without BL2 (MCUboot). We
test this on QEMU only (MPS2 AN521).

Signed-off-by: Ioannis Glaropoulos <5921cc8bab7e1d4329f52fd8f6268f9692e3de80@nordicsemi.no>

finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr