semihosting/uaccess: Avoid including 'cpu.h'

"semihosting/uaccess.h" only requires the following headers:

  - "exec/cpu-defs.h" for target_ulong,
  - "exec/cpu-common.h" for cpu_memory_rw_debug()
  - "exec/tswap.h" for tswap32() and tswap64().

Include them instead of the huge "cpu.h".

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <42c6471e-8383-45e0-85ee-e20ca32ecbad@linaro.org>

include/semihosting/uaccess.h

@@ -14,7 +14,9 @@
 #error Cannot include semihosting/uaccess.h from user emulation
 #endif
 
-#include "cpu.h"
+#include "exec/cpu-common.h"
+#include "exec/cpu-defs.h"
+#include "exec/tswap.h"
 
 #define get_user_u64(val, addr)                                         \
     ({ uint64_t val_ = 0;                                               \