HID: i2c-hid: use correct type for ACPI _DSM parameter

ACPI 5.0 specification requires the fourth parameter to the _DSM (Device
Specific Method) to be of type package instead of integer. Failing to do
that we get following warning on the console:

  ACPI Warning: \_SB_.PCI0.I2C1.TPL0._DSM: Argument #4 type mismatch - Found [Integer],
                ACPI requires [Package] (20130517/nsarguments-95)

Fix this by passing an empty package to the _DSM method. The HID over I2C
specification doesn't require any specific values to be passed with this
parameter.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>