MAINTAINERS: add maintainers for Alibaba' T-Head PMU driver

Add maintainers for Alibaba PMU document and driver

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220818031822.38415-4-xueshuai@linux.alibaba.com


Signed-off-by: Will Deacon <will@kernel.org>