Document EHABI enabled by default

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200390 91177308-0d34-0410-b5e6-96231b3b80d8
Remove -arm-enable-ehabi from Android build rules. It's enabled by default.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200391 91177308-0d34-0410-b5e6-96231b3b80d8