HID: intel-ish-hid: Add driver_data for specifying the firmware filename

Introduces a new structure, ishtp_driver_data, to hold driver-specific
data, including the firmware filename for different hardware variants of
the Intel Integrated Sensor Hub (ISH).

Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>