platform/x86: acer-wmi: Using zero as first WMI instance number

Pali Rohár found that there have some wmi query/evaluation
code that they used 'one' as the first WMI instance number.
But the number is indexed from zero that it's must less than
the instance_count in _WDG.

This patch changes those instance number from one to zero.

Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>