tcg: Remove TCG_TARGET_CON_STR_H

All backends have now been converted to tcg-target-con-str.h,
so we can remove the fallback code.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/tci/tcg-target.h

@@ -207,6 +207,4 @@ static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx,
     /* no need to flush icache explicitly */
 }
 
-#define TCG_TARGET_CON_STR_H
-
 #endif /* TCG_TARGET_H */