dmaengine: dw-edma: Release requested IRQs on failure

From very beginning of the DW eDMA driver live in the kernel the method
dw_edma_irq_request() hasn't been designed quite correct. In case if the
request_irq() method fails to initialize the IRQ handler at some point the
previously requested IRQs will be left initialized. It's prune to errors
up to the system crash. Let's fix that by releasing the previously
requested IRQs in the cleanup-on-error path of the dw_edma_irq_request()
function.

Fixes: e63d79d1 ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>