platform/x86: intel_menlow: avoid null pointer deference error

Fix a null pointer deference by acpi_driver_data() if device is
null (dereference before check). We should only set cdev and check
this is OK after we are sure device is not null.

Signed-off-by: Young Xiao <92siuyang@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>