HID: cp2112: convert to use hid_hw_raw_request()

Commit cafebc0 ("HID: remove hid_get_raw_report in struct hid_device")
obsoletes the use of hdev->hid_get_raw_report(), as calling
hid_hw_raw_request() is functionally equivalent.

Convert cp2112 to use this notation.

Reported-by: fengguang.wu@intel.com
Signed-off-by: Jiri Kosina <jkosina@suse.cz>