Remove redundant cmake options

These are all already included in the default %cmake flags.

ldc.spec

@@ -188,10 +188,8 @@ make %{?_smp_mflags}
 popd
 %endif
 
-%cmake -DMULTILIB:BOOL=OFF -DBUILD_SHARED_LIBS:BOOL=ON       \
+%cmake -DMULTILIB:BOOL=OFF \
        -DINCLUDE_INSTALL_DIR:PATH=%{_includedir}/d           \
-       -DSYSCONF_INSTALL_DIR:PATH=%{_sysconfdir}             \
-       -DCMAKE_INSTALL_PREFIX:PATH=%{_prefix}                \
        -DBASH_COMPLETION_COMPLETIONSDIR:PATH=%{_datadir}/bash-completion/completions \
        -DLLVM_CONFIG:PATH=llvm-config-%{?llvm_version:%{llvm_version}-}%{__isa_bits} \
 %if 0%{?bootstrap_stage2}