x11-wm/nscde: fix packaging when uname -m != uname -p

pkg-static: Unable to access file /wrkdirs/usr/ports/x11-wm/nscde/work/stage/usr/local/lib/NsCDE/FreeBSD_powerpc64/XOverrideFontCursor.so:No such file or directory
pkg-static: Unable to access file /wrkdirs/usr/ports/x11-wm/nscde/work/stage/usr/local/libexec/NsCDE/FreeBSD_powerpc64/colorpicker:No such file or directory
pkg-static: Unable to access file /wrkdirs/usr/ports/x11-wm/nscde/work/stage/usr/local/libexec/NsCDE/FreeBSD_powerpc64/fpclock:No such file or directory