HBSD: Change INSTALL_TARGET in x11-toolkits/tk86
This is a temporary fix to build x11-toolkits/tk86. tcl86 hates being compiled with a full #llvm compiler toolchain [1].
[1] https://twitter.com/lattera/status/1470047195965624326
Signed-off-by: Loic loic.f@hardenedbsd.org