Enable equeue to compile on Mac

Use the same configuration as for Unix as these are broadly compatible.

Author: bulislaw

events/internal/equeue_platform.h

@@ -35,7 +35,7 @@ extern "C" {
 // Try to infer a platform if none was manually selected
 #if !defined(EQUEUE_PLATFORM_POSIX)     \
  && !defined(EQUEUE_PLATFORM_MBED)
-#if defined(__unix__)
+#if defined(__unix__) || defined(__APPLE__)
 #define EQUEUE_PLATFORM_POSIX
 #elif defined(__MBED__)
 #define EQUEUE_PLATFORM_MBED