MAINTAINERS: Demote Gustavo Pimentel to DW EDMA driver reviewer

No maintaining actions from Gustavo have been noticed for over a year.
Demote him to being the DW eDMA driver reviewer for now.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20230511190902.28896-13-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>