sparc64: fix 32bit load sign extension

- change return type of ldl_* to uint32_t to prevent unwanted sign extension
  visible in sparc64 load alternate address space methods
- note this change makes ldl_* softmmu implementations match ldl_phys one
Signed-off-by: NIgor V. Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

softmmu_header.h

@@ -60,7 +60,7 @@
 #if DATA_SIZE == 8
 #define RES_TYPE uint64_t
 #else
-#define RES_TYPE int
+#define RES_TYPE uint32_t
 #endif
 
 #if ACCESS_TYPE == (NB_MMU_MODES + 1)