test_build_sensors_a_m: disable app memory

We run into the limit of 32 object files on ARM when
CONFIG_APPLICATION_MEMORY is enabled.

Bug #7703 filed, meanwhile just disable it, it's not
needed for this test case.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

tests/drivers/build_all/testcase.yaml

@@ -29,6 +29,9 @@ tests:
     platform_exclude: zedboard_pulpino frdm_kw41z
     tags: drivers footprint
     depends_on: adc spi
+    # FIXME see #7703
+    extra_configs:
+      - CONFIG_APPLICATION_MEMORY=n
   test_build_sensors_n_z:
     build_only: true
     extra_args: CONF_FILE=sensors_n_z.conf