Rework enum ProcessField

Use only one enum instead of a global and a platform specific one.
Drop Platform_numberOfFields global variable.
Set known size of Process_fields array

dragonflybsd/ProcessField.h

@@ -0,0 +1,17 @@
+#ifndef HEADER_DragonFlyBSDProcessField
+#define HEADER_DragonFlyBSDProcessField
+/*
+htop - dragonflybsd/ProcessField.h
+(C) 2020 htop dev team
+Released under the GNU GPLv2, see the COPYING file
+in the source distribution for its full text.
+*/
+
+
+#define PLATFORM_PROCESS_FIELDS  \
+   JID   = 100,                  \
+   JAIL  = 101,                  \
+   // End of list
+
+
+#endif /* HEADER_DragonFlyBSDProcessField */