MAINTAINERS: Remove Gabriele Paoloni as HiSilicon PCI maintainer

Gabriele is now moving to a different role, so remove him as HiSilicon PCI
maintainer.

Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
[bhelgaas: Thanks for all your help, Gabriele, and best wishes!]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Zhou Wang <wangzhou1@hisilicon.com>