samples: matter: thermostat: Enable LTO for nRF7002 DK

Enable LTO for `nrf7002dk/nrf5340/cpuapp` due to increased flash usage.

Signed-off-by: Adrian Gielniewski <[email protected]>

Author: adigie

samples/matter/thermostat/boards/nrf7002dk_nrf5340_cpuapp.conf

@@ -0,0 +1,9 @@
+#
+# Copyright (c) 2024 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+# Enable LTO to decrease the flash usage.
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y