esp_common: Don't redefine likely/unlikely if already defined

As these macros aren't namespaced, they may have been defined by another header.

Also reported in https://github.com/espressif/esp-idf/issues/6445

components/esp_common/include/esp_compiler.h

@@ -23,12 +23,20 @@
  * code.
  */
 #if (CONFIG_COMPILER_OPTIMIZATION_PERF)
+#ifndef likely
 #define likely(x)      __builtin_expect(!!(x), 1)
+#endif
+#ifndef unlikely
 #define unlikely(x)    __builtin_expect(!!(x), 0)
+#endif
 #else
+#ifndef likely
 #define likely(x)      (x)
+#endif
+#ifndef unlikely
 #define unlikely(x)    (x)
 #endif
+#endif
 
 /*
  * Utility macros used for designated initializers, which work differently