cc.cmake: use -force_cpusubtype_ALL for Darwin PPC

cmake/cc.cmake

@@ -286,12 +286,18 @@ if (${CORE} STREQUAL PPC970)
   if (NOT DYNAMIC_ARCH)
     set (CCOMMON_OPT  "${CCOMMON_OPT} -mcpu=970 -mtune=970 -maltivec -fno-fast-math")
   endif ()
+  if (APPLE)
+    set (CCOMMON_OPT  "${CCOMMON_OPT} -force_cpusubtype_ALL")
+  endif ()
 endif ()
 
 if (${CORE} STREQUAL PPCG4)
   if (NOT DYNAMIC_ARCH)
     set (CCOMMON_OPT  "${CCOMMON_OPT} -mcpu=G4 -mtune=G4 -maltivec -fno-fast-math")
   endif ()
+  if (APPLE)
+    set (CCOMMON_OPT  "${CCOMMON_OPT} -force_cpusubtype_ALL")
+  endif ()
 endif ()
 
 if (NOT DYNAMIC_ARCH)