HID: lenovo: Rename hid-lenovo-tpkbd to hid-lenovo

Rename module and all functions within so we can add support for other
keyboards in the same file. Rename the _tp postfix to _tpkbd, to
signify functions relevant to the TP USB keyboard.

Signed-off-by: Jamie Lentin <jm@lentin.co.uk>
Reviewed-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>