[Hexagon] Add missing MIRParser link dependency (#191010)
cd66d79be19b added parseMachineFunctionInfo to HexagonTargetMachine
which calls parseNamedRegisterReference from LLVMMIRParser, but did not
add the library dependency. This causes link failures for executables
like dsymutil and llvm-split when building with BUILD_SHARED_LIBS=OFF.
Add MIRParser to LINK_COMPONENTS.
