hwdb: Enable JP-IK LEAP W502's touchpad toggle key

hwdb: Enable JP-IK LEAP W502's touchpad toggle key

The laptop JP-IK LEAP W502 has touchpad toggle key (Fn+F9), but it does
not work. Because, the scancode maps to a wrong key code:

Event: time 1715846095.224900, type 4 (EV_MSC), code 4 (MSC_SCAN), value 9d
Event: time 1715846095.224900, type 1 (EV_KEY), code 97 (KEY_RIGHTCTRL), value 1
Event: time 1715846095.224900, -------------- SYN_REPORT ------------
Event: time 1715846095.230985, type 4 (EV_MSC), code 4 (MSC_SCAN), value db
Event: time 1715846095.230985, type 1 (EV_KEY), code 125 (KEY_LEFTMETA), value 1
Event: time 1715846095.230985, -------------- SYN_REPORT ------------
Event: time 1715846095.232903, type 4 (EV_MSC), code 4 (MSC_SCAN), value 76
Event: time 1715846095.232903, type 1 (EV_KEY), code 85 (KEY_ZENKAKUHANKAKU), value 1
Event: time 1715846095.232903, -------------- SYN_REPORT ------------

Map the scancode 76 to KEY_F21 to enable the touchpad toggle key.