platform/x86: intel_scu_ipcutil: Remove default y from Kconfig

This driver is by no means essential for system to boot up so remove
default y from it.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>