usb: hid: All hid_ops callbacks get device pointer.

This commit extends USB hid API callbacks by adding
'const struct device *dev' parameter. If the application
configured more than one HID device then it must specify
separate hid_ops for each device as its unable to determine
for which device the callback was called.

This patch makes it possible to have only one hid_ops within
the application and the application is aware for which device
the callback was called because of explicit device pointer.

Signed-off-by: Emil Obalski <emil.obalski@nordicsemi.no>