HBSD: Disable DTRACE option in lang/ghc
DTRACE support is broken with a complete llvm compiler toolchain.
Its deactivation fix the following problem:
objcopy: error: Link field value 38 in section .rela.SUNW_dof is not a symbol table
dtrace: failed to link script rts/RtsProbes.d: failed to link rts/dist/build/RtsProbes.o: objcopy exited with status 1
Signed-off-by: Loic <loic.f@hardenedbsd.org>