android: add support for libLLVMTextAPI

android: add support for libLLVMTextAPI

Fixes the following building errors:

external/llvm/include/llvm/TextAPI/MachO/Symbol.h:66: error: undefined reference to
'llvm::MachO::mapToArchitectureSet(llvm::ArrayRef<llvm::MachO::Target>)'
external/llvm/include/llvm/TextAPI/MachO/InterfaceFile.h:191: error: undefined reference to
'llvm::MachO::mapToPlatformSet(llvm::ArrayRef<llvm::MachO::Target>)'
external/llvm/lib/Object/TapiUniversal.cpp:25: error: undefined reference to
'llvm::MachO::TextAPIReader::get(llvm::MemoryBufferRef)'
external/llvm/include/llvm/TextAPI/MachO/InterfaceFile.h:185: error: undefined reference to
'llvm::MachO::mapToArchitectureSet(llvm::ArrayRef<llvm::MachO::Target>)'