Revert "char: misc: make miscdevice unit test built-in only"

This reverts commit 20acf4d.

It still does not fix the build issue on all arches, so revert the whole
series for now until it can come back in a "clean" form.

Link: https://lore.kernel.org/r/20250501164501.0fc0ab68@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: gregkh

lib/Kconfig.debug

@@ -2512,7 +2512,7 @@ config TEST_IDA
 	tristate "Perform selftest on IDA functions"
 
 config TEST_MISC_MINOR
-	bool "miscdevice KUnit test" if !KUNIT_ALL_TESTS
+	tristate "miscdevice KUnit test" if !KUNIT_ALL_TESTS
 	depends on KUNIT
 	default KUNIT_ALL_TESTS
 	help