cxgbe(4): Remove some dead code.

MFC after:	3 days

sys/dev/cxgbe/adapter.h

@@ -68,16 +68,6 @@ MALLOC_DECLARE(M_CXGBE);
 #define CXGBE_UNIMPLEMENTED(s) \
     panic("%s (%s, line %d) not implemented yet.", s, __FILE__, __LINE__)
 
-#if defined(__i386__) || defined(__amd64__)
-static __inline void
-prefetch(void *x)
-{
-	__asm volatile("prefetcht0 %0" :: "m" (*(unsigned long *)x));
-}
-#else
-#define prefetch(x) __builtin_prefetch(x)
-#endif
-
 #ifndef SYSCTL_ADD_UQUAD
 #define SYSCTL_ADD_UQUAD SYSCTL_ADD_QUAD
 #define sysctl_handle_64 sysctl_handle_quad

sys/dev/cxgbe/iw_cxgbe/iw_cxgbe.h

@@ -56,8 +56,6 @@
 #include <rdma/ib_verbs.h>
 #include <rdma/iw_cm.h>
 
-#undef prefetch
-
 #include "common/common.h"
 #include "common/t4_msg.h"
 #include "common/t4_regs.h"