of: Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n

Some configurations want to enable CONFIG_KUNIT without enabling
CONFIG_OF_OVERLAY. The kunit overlay code already skips if
CONFIG_OF_OVERLAY isn't enabled, so this select here isn't really doing
anything besides making it easier to run the tests without them
skipping. Remove the select and move the config setting to the
drivers/of/.kunitconfig file so that the overlay tests can be run with
or without CONFIG_OF_OVERLAY set to test either behavior.

Fixes: 5c9dd72 ("of: Add a KUnit test for overlays and test managed APIs")
Signed-off-by: Stephen Boyd <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Rob Herring (Arm) <[email protected]>

Author: bebarino

drivers/of/.kunitconfig

@@ -1,4 +1,5 @@
 CONFIG_KUNIT=y
 CONFIG_OF=y
 CONFIG_OF_KUNIT_TEST=y
+CONFIG_OF_OVERLAY=y
 CONFIG_OF_OVERLAY_KUNIT_TEST=y

drivers/of/Kconfig

@@ -111,7 +111,7 @@ config OF_OVERLAY_KUNIT_TEST
 	tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS
 	depends on KUNIT
 	default KUNIT_ALL_TESTS
-	select OF_OVERLAY
+	select DTC
 	help
 	  This option builds KUnit unit tests for the device tree overlay code.
 

drivers/of/overlay_test.c

@@ -65,6 +65,8 @@ static void of_overlay_apply_kunit_cleanup(struct kunit *test)
 	struct device_node *np;
 
 	of_root_kunit_skip(test);
+	if (!IS_ENABLED(CONFIG_OF_OVERLAY))
+		kunit_skip(test, "requires CONFIG_OF_OVERLAY to apply overlay");
 	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
 		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");