efi_selftest: allow to select a single test for execution

Environment variable efi_selftest is passed as load options
to the selftest application. It is used to select a single
test to be executed.

The load options are an UTF8 string. Yet I decided to keep
the name propertiy of the tests as char[] to reduce code
size.

Special value 'list' displays a list of all available tests.

Tests get an on_request property. If this property is set
the tests are only executed if explicitly requested.

The invocation of efi_selftest is changed to reflect that
bootefi selftest with efi_selftest = 'list' will call the
Exit bootservice.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_selftest/efi_selftest_util.c

@@ -23,3 +23,12 @@ int efi_st_memcmp(const void *buf1, const void *buf2, size_t length)
 	}
 	return 0;
 }
+
+int efi_st_strcmp_16_8(const u16 *buf1, const char *buf2)
+{
+	for (; *buf1 || *buf2; ++buf1, ++buf2) {
+		if (*buf1 != *buf2)
+			return *buf1 - *buf2;
+	}
+	return 0;
+}