gve: Remove obsolete checks that rely on page size.

gve: Remove obsolete checks that rely on page size.

These checks are safe to remove as they are no longer enforced by the
backend. Retaining them would require updating them to work differently
with page sizes larger than 4k.

Signed-off-by: Jordan Kimbrough <jrkim@google.com>
Signed-off-by: John Fraker <jfraker@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231128002648.320892-4-jfraker@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>