gpio: acpi: Skip _AEI entries without a handler rather then aborting the scan

acpi_walk_resources will stop as soon as the callback passed in returns
an error status. On a x86 tablet I have the first GpioInt in the _AEI
resource list has no handler defined in the DSDT, causing
acpi_walk_resources to abort scanning the rest of the resource list,
which does define valid ACPI GPIO events.

This commit changes the return for not finding a handler from
AE_BAD_PARAMETER to AE_OK so that the rest of the resource list will
get scanned normally in case of missing event handlers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>