MAINTAINERS: Add Manivannan to DW eDMA driver maintainers list

Manivannan has been very active in reviewing the bits coming to the DW
eDMA driver. Let's add him to the driver maintainers list.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20230511190902.28896-14-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>