ftrace: Add update_ftrace_direct_mod function

ftrace: Add update_ftrace_direct_mod function

Adding update_ftrace_direct_mod function that modifies all entries
(ip -> direct) provided in hash argument to direct ftrace ops and
updates its attachments.

The difference to current modify_ftrace_direct is:
- hash argument that allows to modify multiple ip -> direct
  entries at once

This change will allow us to have simple ftrace_ops for all bpf
direct interface users in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20251230145010.103439-7-jolsa@kernel.org