samples: wifi: wfa_qt_app: Fix Flash overflow for enterprise

Enable LTO to fix the overflow and also to make room for future
increase.

Signed-off-by: Chaitanya Tata <[email protected]>

Author: krish2718

samples/wifi/wfa_qt_app/overlay-enterprise.conf

@@ -1,3 +1,6 @@
 CONFIG_NRF_WIFI_DATA_HEAP_SIZE=80000
 CONFIG_WIFI_CREDENTIALS=n
 CONFIG_NRF70_RX_NUM_BUFS=16
+# Link-time optimizations to fix flash overflow
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y