dmaengine: zx: remove redundant irqsave in hardIRQ

Running in hardIRQ context, disabling IRQ is redundant.

Cc: Jun Nie <jun.nie@linaro.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20200912094036.32112-1-song.bao.hua@hisilicon.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>