Do not propagate DYNAMIC_ARCH to CFLAGS if it is not supported on the architecture

cmake/system.cmake

@@ -199,10 +199,12 @@ if (NEED_PIC)
   endif()
 endif ()
 
-if (DYNAMIC_ARCH)
-  set(CCOMMON_OPT "${CCOMMON_OPT} -DDYNAMIC_ARCH")
-  if (DYNAMIC_OLDER)
-    set(CCOMMON_OPT "${CCOMMON_OPT} -DDYNAMIC_OLDER")
+if (X86 OR X86_64 OR ARM64 OR PPC)
+  if (DYNAMIC_ARCH)
+    set(CCOMMON_OPT "${CCOMMON_OPT} -DDYNAMIC_ARCH")
+    if (DYNAMIC_OLDER)
+      set(CCOMMON_OPT "${CCOMMON_OPT} -DDYNAMIC_OLDER")
+    endif ()
   endif ()
 endif ()