"exec/cpu-defs.h" contains generic CPU definitions for the
TCG frontends (mostly related to TLB). TCG backends definitions
aren't relevant here.

See tcg/README description:

  4) Backend

  tcg-target.h contains the target specific definitions. tcg-target.c.inc
  contains the target specific code; it is #included by tcg/tcg.c, rather
  than being a standalone C file.

So far only "tcg/tcg.h" requires these headers.

Remove the "target-tcg.h" header dependency on TCG frontends, so we
don't have to rebuild all frontends when hacking a single backend.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210204191423.1754158-1-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>