man/weston.ini: Fix panel-position

It was renamed from panel-location in
55d5701ddf, and gained a few possible
values.

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Reviewed-by: Daniel Stone <daniels@collabora.com>

man/weston.ini.man

@@ -236,9 +236,12 @@ digit pairs are in order transparency, red, green, and blue. Examples:
 .fi
 .RE
 .TP 7
-.BI "panel-location=" top
-sets the location of the panel (string). Can be
+.BI "panel-position=" top
+sets the position of the panel (string). Can be
 .B top,
+.B bottom,
+.B left,
+.B right,
 .B none.
 .TP 7
 .BI "locking=" true