autofs: fails to compile with openldap disabled

As of 5.0.6, it appears that changes were introduced so that if you
compile with openldap disabled and openldap headers are not available,
then autofs fails to build.

Since autofs no longer depends on openldap, remove the dependency.

Signed-off-by: Amy Fong <amy.fong@windriver.com>
Signed-off-by: Joe MacDonald <joe.macdonald@windriver.com>