target/ppc: Include missing 'exec/target_long.h' header

The "exec/target_long.h" header is indirectly included, pulled
via "exec/cpu-defs.h". Include it explicitly otherwise we'd get
when removing the latter:

  target/ppc/cpu.h:1281:5: error: unknown type name 'target_ulong'
   1281 |     target_ulong gpr[32];  /* general purpose registers */
        |     ^
  hw/ppc/spapr_ovec.h:76:44: error: unknown type name 'target_ulong'
         76 | SpaprOptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector);
            |                                            ^

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20260313062055.2188-13-philmd@linaro.org>

include/hw/ppc/spapr_ovec.h

@@ -37,7 +37,7 @@
 #ifndef SPAPR_OVEC_H
 #define SPAPR_OVEC_H
 
-#include "cpu.h"
+#include "exec/target_long.h"
 
 typedef struct SpaprOptionVector SpaprOptionVector;
 

target/ppc/cpu.h

@@ -25,6 +25,7 @@
 #include "exec/cpu-common.h"
 #include "exec/cpu-defs.h"
 #include "exec/cpu-interrupt.h"
+#include "exec/target_long.h"
 #include "cpu-qom.h"
 #include "qom/object.h"
 #include "hw/core/registerfields.h"