scripts: ci: check_compliance: Add sysbuild Kconfig exceptions

Adds exceptions for Kconfigs which sysbuild uses when configuring
MCUboot.

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

scripts/ci/check_compliance.py

@@ -612,6 +612,8 @@ def check_no_undef_outside_kconfig(self, kconf):
                               # toolchain Kconfig which is sourced based on
                               # Zephyr toolchain variant and therefore not
                               # visible to compliance.
+        "BOOT_ENCRYPTION_KEY_FILE", # Used in sysbuild
+        "BOOT_ENCRYPT_IMAGE", # Used in sysbuild
         "BOOT_UPGRADE_ONLY", # Used in example adjusting MCUboot config, but
                              # symbol is defined in MCUboot itself.
         "BOOT_SERIAL_BOOT_MODE",     # Used in (sysbuild-based) test/