QNX: Update qcc depfile flags to be compliant with ccache

Pass the flags to the preprocessor phase via `-Wp,`.  This is
accepted both by qcc and ccache.

Modules/Compiler/QCC.cmake

@@ -11,7 +11,7 @@ macro(__compiler_qcc lang)
   set(CMAKE_${lang}_COMPILE_OPTIONS_TARGET "-V")
 
   set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-Wp,-isystem,")
-  set(CMAKE_DEPFILE_FLAGS_${lang} "-Wc,-MD,<DEPFILE>,-MT,<OBJECT>,-MF,<DEPFILE>")
+  set(CMAKE_DEPFILE_FLAGS_${lang} "-Wp,-MD,<DEPFILE> -Wp,-MT,<OBJECT> -Wp,-MF,<DEPFILE>")
 
   set(CMAKE_${lang}_LINKER_WRAPPER_FLAG "-Wl,")
   set(CMAKE_${lang}_LINKER_WRAPPER_FLAG_SEP ",")