MFH: r542055

x11/xkeyboard-config: Add NLS option

Add NLS option to x11/xkeyboard-config. This was broken in the past, but is
fixed now.

PR: 243070 (based on)
Submitted by: Andrew Romanenko
Event: Julu 2020 bugathon

Approved by: ports-secteam (joenum)