Map the ACPI tables into the DMAP

When we try to load these tables via acpidump(8) we need them to be in
the DMAP for /dev/mem to access. Add the EFI ACPI reclaim memory type
to the list of memory we map into DMAP but not used by the kernel as
this is the recommended place to put these.

Sponsored by:	The FreeBSD Foundation

sys/arm64/arm64/machdep.c

@@ -486,6 +486,11 @@ add_efi_map_entry(struct efi_md *p)
 {
 
 	switch (p->md_type) {
+	case EFI_MD_TYPE_RECLAIM:
+		/*
+		 * The recomended location for ACPI tables. Map into the
+		 * DMAP so we can access them from userspace via /dev/mem.
+		 */
 	case EFI_MD_TYPE_RT_CODE:
 		/*
 		 * Some UEFI implementations put the system table in the