Remove define of SA_EXPOSE_TAGBITS.

This is in the uapi headers now.

Test: Builds and treehugger.
Change-Id: I0dcebeec722ae2835a1054ee8b39329cd06799d4

debuggerd/handler/debuggerd_handler.cpp

@@ -838,7 +838,6 @@ void debuggerd_init(debuggerd_callbacks_t* callbacks) {
   // Use the alternate signal stack if available so we can catch stack overflows.
   action.sa_flags |= SA_ONSTACK;
 
-#define SA_EXPOSE_TAGBITS 0x00000800
   // Request that the kernel set tag bits in the fault address. This is necessary for diagnosing MTE
   // faults.
   action.sa_flags |= SA_EXPOSE_TAGBITS;