meson, configure: move --with-pkgversion, CONFIG_STAMP to meson

The hash is now generated with a Python script.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/meson-buildoptions.py

@@ -36,6 +36,7 @@ SKIP_OPTIONS = {
 
 OPTION_NAMES = {
     "malloc": "enable-malloc",
+    "pkgversion": "with-pkgversion",
     "trace_backends": "enable-trace-backends",
     "trace_file": "with-trace-file",
 }