platform/x86: samsung-laptop: Initialize loca variable

The variable is used uninitialized which might come into unexpected
behaviour on some Samsung laptops.

Initialize it to 0xffff which seems a proper value for non-supported
feature.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>