coreinfo/coreinfo.c: Correct main function signature

libpayload passes argc and argv to main(), and ignoring these arguments
causes a compile time error when using LTO.

Change-Id: I5d2b30158ebabe1d1534a9684874018483ad769b
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38292
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

payloads/coreinfo/coreinfo.c

@@ -290,8 +290,11 @@ static void loop(void)
 	}
 }
 
-int main(void)
+int main(int argc, char **argv)
 {
+	(void)argc;
+	(void)argv;
+
 	int j;
 
 	if (CONFIG(LP_USB))