platform/x86: acerhdf: Add BIOS entry for Gateway LT31 v1.3307

To fix:

  acerhdf: unknown (unsupported) BIOS version Gateway  /LT31   /v1.3307 , please report, aborting!

As can be seen in the context, the BIOS registers haven't changed in
the previous versions, so the assumption is they won't have changed
in this last update for this somewhat older platform either.

Cc: Peter Feuerer <peter@piie.net>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Feuerer <peter@piie.net>