HID: playstation: Add DualSense Edge extra button support

HID: playstation: Add DualSense Edge extra button support

The DualSense Edge controller (product ID 0x0df2) has four additional
buttons compared to the standard DualSense: two front function buttons
(Fn1 and Fn2) and two rear paddles (left and right). These are reported
in bits 4-7 of buttons[2] in the input report.

Map them to BTN_TRIGGER_HAPPY1 through BTN_TRIGGER_HAPPY4 so that
userspace applications can use these extra inputs. An is_edge flag
gates the extra button handling based on the product ID.

Signed-off-by: Aaron Webster <awebster@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>