[mips][compiler-rt] Disable sem_init_glibc.cc for MIPS64.

This test can't pass on MIPS64 due to the lack of versioned interceptors
for asan and company. The interceptors bind to the earlier version of
sem_init rather than the latest version. For MIPS64el this causes an
accidental pass while MIPS64 big endian fails due reading back a
different 32bit word to what sem_init wrote when the test is corrected
to use 64bit atomics.

llvm-svn: 314100