[nrf fromtree] samples: settings: Enable NVS backend on mimxrt1020_evk board

The tests for settings will not work properly with just provided config
file for mimxrt1020:
west build -p always -b mimxrt1020_evk samples/subsys/settings

as there the settings_save_one() would return -2 (-ENOENT) as by default
the CONFIG_SETTINGS_NONE is defined for mimxrt1020 configuration.

For proper operation (i.e. to have a memory medium to store settings
values) the NVS backend needs to be enabled.

Signed-off-by: Lukasz Majewski <[email protected]>

Signed-off-by: Sebastian Głąb <[email protected]>
(cherry picked from commit 8719aba)

Author: nordic-segl

samples/subsys/settings/boards/mimxrt1020_evk.conf

@@ -0,0 +1,2 @@
+CONFIG_NVS=y
+CONFIG_SETTINGS_NVS=y