ci: use test_progs -l option to generate the list of whitelisted tests

Use this list of enabled tests as a whitelist, so that we don't have to
keep updating BLACKLIST-5.5.0 anymore. I'll keep BLACKLIST-5.5.0 for
now, because it serves as a nice historic log of which tests depend on
which kernels.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

travis-ci/vmtest/configs/whitelist/WHITELIST-5.5.0

@@ -0,0 +1,55 @@
+attach_probe
+autoload
+bpf_verif_scale
+cgroup_attach_autodetach
+cgroup_attach_override
+core_autosize
+core_extern
+core_read_macros
+core_reloc
+core_retro
+cpu_mask
+endian
+fexit_stress
+get_branch_snapshot
+get_stackid_cannot_attach
+global_data
+global_data_init
+global_func_args
+hashmap
+l4lb_all
+linked_funcs
+linked_maps
+map_lock
+obj_name
+perf_buffer
+perf_event_stackmap
+pinning
+pkt_md_access
+probe_user
+queue_stack_map
+raw_tp_writable_reject_nbd_invalid
+raw_tp_writable_test_run
+rdonly_maps
+section_names
+signal_pending
+skeleton
+sockmap_ktls
+sockopt
+sockopt_inherit
+sockopt_multi
+spinlock
+stacktrace_map
+stacktrace_map_raw_tp
+static_linked
+subprogs
+task_fd_query_rawtp
+task_fd_query_tp
+tc_bpf
+tcp_estats
+tcp_rtt
+tp_attach_query
+xdp
+xdp_info
+xdp_noinline
+xdp_perf