arm64: Fix the includes for rsi.c

This depended on header pollution only present when FDT is defined. As
FDT isn't check for in this file we can remove opt_platform.h and
include the correct set of vm header files.

Reported by:	ivy
Fixes:	76a2904c35 ("arm64: Add RSI detection for CCA")
Sponsored by:	Arm Ltd

sys/arm64/arm64/rsi.c

@@ -25,14 +25,13 @@
  * SUCH DAMAGE.
  */
 
-#include "opt_platform.h"
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/physmem.h>
 #include <sys/rwlock.h>
 
-#include <vm/vm_page.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>
 
 #include <machine/rsi.h>
 #include <machine/vmparam.h>