selftests/mm: fix comment for check_test_requirements

selftests/mm: fix comment for check_test_requirements

The test supports arm64 as well so the comment is incorrect.  And there's
a check for arm64 in va_high_addr_switch.c.

Link: https://lkml.kernel.org/r/20251221040025.3159990-5-chuhu@redhat.com
Fixes: 983e760bcdb6 ("selftest/mm: va_high_addr_switch: add ppc64 support check")
Fixes: f556acc2facd ("selftests/mm: skip test for non-LPA2 and non-LVA systems")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Reviewed-by: Luiz Capitulino <luizcap@redhat.com>
Cc: "David Hildenbrand (Red Hat)" <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>