MAINTAINERS: Update KPROBES and TRACING entries

MAINTAINERS: Update KPROBES and TRACING entries

There is no git tree for KPROBES in MAINTAINERS, it is not convinent to
rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, so add
git tree and missing files for KPROBES, and also use linux-trace.git for
TRACING to avoid confusing.

Link: https://lkml.kernel.org/r/1635213091-24387-5-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>