idma64: Don't try to serve interrupts when device is powered off

[ Upstream commit 9140ce47 ]

When iDMA 64-bit device is powered off, the IRQ status register
is all 1:s. This is never happen in real case and signalling that
the device is simply powered off. Don't try to serve interrupts
that are not ours.

Fixes: 667dfed9

 ("dmaengine: add a driver for Intel integrated DMA 64-bit")
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Closes: https://lore.kernel.org/r/700bbb84-90e1-4505-8ff0-3f17ea8bc631@gmail.com
Tested-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240321120453.1360138-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>