docs: mm: Fix number of base pages for 1GB HugeTLB

1GB HugeTLB page consists of 262144 base pages.
Signed-off-by: Usama Arif <usama.arif@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230207114456.2304801-1-usama.arif@bytedance.com

Documentation/mm/vmemmap_dedup.rst

+
 .. SPDX-License-Identifier: GPL-2.0
 
 =========================================
@@ -17,7 +18,7 @@ HugeTLB pages consist of multiple base page size pages and is supported by many
 architectures. See Documentation/admin-guide/mm/hugetlbpage.rst for more
 details. On the x86-64 architecture, HugeTLB pages of size 2MB and 1GB are
 currently supported. Since the base page size on x86 is 4KB, a 2MB HugeTLB page
-consists of 512 base pages and a 1GB HugeTLB page consists of 4096 base pages.
+consists of 512 base pages and a 1GB HugeTLB page consists of 262144 base pages.
 For each base page, there is a corresponding ``struct page``.
 
 Within the HugeTLB subsystem, only the first 4 ``struct page`` are used to