subsys/settings: Remove optional from Kconfig

Kconfig does not set SETTINGS_NONE as default backend (meaning no
backend) because SETTINGS_NONE is optional. There is no difference
between SETTINGS_NONE and SETTINGS_CUSTOM. By removing the optional line
SETTINGS_NONE is selected as default, to use a custom backend
SETTINGS_CUSTOM=y must be set.

Signed-off-by: Laczen JMS <laczenjms@gmail.com>
1 file changed