MAINTAINERS: add maintainers for delaytop

The delaytop tool supports showing system delays and task-level delays,
effectively identifying the top-n tasks with high latency in the system,
which is highly beneficial for improving system performance.  Wang Yaxin
and her colleague Fan Yu focus on locating system delay issues.  To
promote the thriving development of delaytop, we hope to serve as
maintainers to continuously improve it, aiming to provide a more effective
solution for system latency issues in the future.

Link: https://lkml.kernel.org/r/20250721094049958ImB8XG_imntcPqpQn1KfG@zte.com.cn


Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Fan Yu <fan.yu9@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>