Clat eBPF is always enabled (and required)

Android S requires devices to support eBPF, additionally ClatEbpfMaybe
was only used to reduce some errors to informational logging.

This is no longer worth it, as launch Q devices will never trigger
this, and if anyone decides to upgrade a 4.9+ Pie device they can
simply enable the relevant options (such devices are likely already
running Q era kernels anyway...).

ie. CONFIG_NET_SCH_INGRESS and CONFIG_NET_CLS_BPF are required

Test: builds, atest, TreeHugger
Bug: 167500195
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I06dc92d5fd477886aa50e8751cb13710d6b98427