Integrate qemu_cfg_preinit() into qemu_romfile_init().

Now that only qemu_romfile_init() uses the fw_cfg interface, it only
needs to be detected in that function.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/src/paravirt.h b/src/paravirt.h
index 1d06e58..4438273 100644
--- a/src/paravirt.h
+++ b/src/paravirt.h
@@ -25,7 +25,6 @@
 
 void qemu_ramsize_preinit(void);
 void qemu_biostable_setup(void);
-void qemu_cfg_preinit(void);
-void qemu_romfile_init(void);
+void qemu_cfg_init(void);
 
 #endif