Remove support for ancient compilers

We don't support building the kernel from such old compilers, nor with
the Intel Compiler specifically. Remove support for this old construct
that was copied from stdbool.h and not relevant here.

sys/dev/bxe/ecore_sp.h

@@ -75,9 +75,6 @@ typedef volatile int ecore_atomic_t;
 #ifndef __bool_true_false_are_defined
 #ifndef __cplusplus
 #define bool _Bool
-#if __STDC_VERSION__ < 199901L && __GNUC__ < 3 && !defined(__INTEL_COMPILER)
-typedef _Bool bool;
-#endif
 #endif /* !__cplusplus */
 #endif /* !__bool_true_false_are_defined$ */