HID: Extend the interface with report requests

Some drivers send reports directly to underlying device, creating an
unwanted dependency on the underlying transport layer. This patch adds
hid_hw_request() to the interface, thereby removing usbhid from the
lion share of the drivers.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>