evdev: Translate KEY_102ND in evdev_scancode2key()

This is the extra key on 102/105-keys keyboards, located on the right
of the Left Shift key. For instance on a French layout, this is the '<'
key.

This fixes an issue where the key fires no evdev event and thus remains
inactive in an evdev/libinput-enabled X.Org server. The issue only
occurred on an AT keyboard; the same key on a USB keyboard worked fine.

PR: 222609 (only for reference)
Approved by: wulf@
Differential Revision: https://reviews.freebsd.org/D12883