Arm backend: Add arm-ethosu-linux preset file

Add arm-ethosu-linux preset file and wire CMake preset to it

Signed-off-by: per.held@arm.com
Change-Id: Ice800b6fe0eb7befbdd62509cd7186f2977cba25

Author: perheld

CMakePresets.json

@@ -290,13 +290,8 @@
       "name": "arm-ethosu-linux",
       "displayName": "Build ExecuTorch for Arm Ethos-U Linux",
       "inherits": ["common"],
-      "description": "musl declares __assert_fail with int for line; avoid NDEBUG forward-decl mismatch in Release builds",
       "cacheVariables": {
-        "EXECUTORCH_BUILD_ARM_ETHOSU_LINUX": "ON",
-        "EXECUTORCH_BUILD_EXECUTOR_RUNNER": "ON",
-        "EXECUTORCH_BUILD_KERNELS_QUANTIZED": "ON",
-        "CMAKE_C_FLAGS_RELEASE": "-UNDEBUG",
-        "CMAKE_CXX_FLAGS_RELEASE": "-UNDEBUG",
+        "EXECUTORCH_BUILD_PRESET_FILE": "${sourceDir}/tools/cmake/preset/arm_ethosu_linux.cmake",
         "CMAKE_TOOLCHAIN_FILE": "${sourceDir}/examples/arm/ethos-u-setup/aarch64-linux-musl-toolchain.cmake"
       }
     }

tools/cmake/preset/arm_ethosu_linux.cmake

@@ -0,0 +1,19 @@
+# Copyright 2026 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+set_overridable_option(EXECUTORCH_BUILD_ARM_ETHOSU_LINUX ON)
+set_overridable_option(EXECUTORCH_BUILD_EXECUTOR_RUNNER ON)
+set_overridable_option(EXECUTORCH_BUILD_EXTENSION_EVALUE_UTIL ON)
+set_overridable_option(EXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL ON)
+set_overridable_option(EXECUTORCH_BUILD_KERNELS_QUANTIZED ON)
+
+set(CMAKE_C_FLAGS_RELEASE
+    "-UNDEBUG"
+    CACHE STRING "Avoid NDEBUG forward-decl mismatch in musl Release builds"
+)
+set(CMAKE_CXX_FLAGS_RELEASE
+    "-UNDEBUG"
+    CACHE STRING "Avoid NDEBUG forward-decl mismatch in musl Release builds"
+)