Define `TOUCHEVENTF_PEN` if not defined

src/video/windows/SDL_windowsevents.c

@@ -99,6 +99,9 @@
 #ifndef WM_GETDPISCALEDSIZE
 #define WM_GETDPISCALEDSIZE 0x02E4
 #endif
+#ifndef TOUCHEVENTF_PEN
+#define TOUCHEVENTF_PEN 0x0040
+#endif
 
 #ifndef IS_HIGH_SURROGATE
 #define IS_HIGH_SURROGATE(x)   (((x) >= 0xd800) && ((x) <= 0xdbff))