target-alpha, target-ppc: Remove unnecessary setjmp.h include

Remove the include of setjmp.h from the cpu.h of target-alpha
and target-ppc. This is unnecessary because cpu-defs.h already
includes this header; this change brings these two targets
into line with all the rest.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

target-alpha/cpu.h

@@ -28,8 +28,6 @@
 
 #include "cpu-defs.h"
 
-#include <setjmp.h>
-
 #include "softfloat.h"
 
 #define TARGET_HAS_ICE 1

target-ppc/cpu.h

@@ -75,8 +75,6 @@
 
 #include "cpu-defs.h"
 
-#include <setjmp.h>
-
 #include "softfloat.h"
 
 #define TARGET_HAS_ICE 1