[nrf noup] tests: drivers: mspi: disable no_multithreading test

Lilium targets do not support No-Multithreading scenarios.
Disable the corresponding test in MSPI.

Signed-off-by: Riadh Ghaddab <[email protected]>

Author: rghaddab

tests/drivers/mspi/flash/testcase.yaml

@@ -38,7 +38,7 @@ tests:
       - CONFIG_MSPI_DW_HANDLE_FIFOS_IN_SYSTEM_WORKQUEUE=y
   drivers.mspi.flash.mspi_nor_no_multithreading:
     filter: dt_alias_exists("mspi0") and CONFIG_FLASH_MSPI_NOR
-    integration_platforms:
+    platform_exclude:
       - nrf54h20dk/nrf54h20/cpuapp
     extra_configs:
       - CONFIG_MULTITHREADING=n