HID: hid-lenovo-go: Add RGB LED control interface

HID: hid-lenovo-go: Add RGB LED control interface

Adds an LED multicolor class device and attribute group for controlling
the RGB of the Left and right handles. In addition to the standard
led_cdev attributes, additional attributes that allow for the control of
the effect (monocolor, breathe, rainbow, and chroma), speed of the
effect change, an enable toggle, and profile.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>