Disable AArch64 XOM when not using lld.

AArch64 execute-only memory is only supported when using lld as the
linker. There's still a few modules which don't use lld, so in those
cases we need to disable this option.

Bug: 77958880
Test: Module with LOCAL_USE_CLANG_LLD false builds without XOM
Test: Module without LOCAL_USE_CLANG_LLD defined builds with XOM

Change-Id: I5dfe3cd1e1cac2b3ead13912af9f7fe896d507e9