[BOLT][AArch64] Fix BUILD_SHARED_LIBS after #158738 (#160854)
Link BOLTUtils against the AArch64 target to support the new option
that enables instrumentation without LSE (see #158738)
This fixes shared library builds, eg:
https://lab.llvm.org/staging/#/builders/220/builds/1537
Note: the link points to a collapsing builder.