spi: zynqmp-gqspi: Always acknowledge interrupts

RXEMPTY can cause an IRQ, even though we may not do anything about it
(such as if we are waiting for more received data). We must still handle
these IRQs because we can tell they were caused by the device.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://patch.msgid.link/20250116224130.2684544-6-sean.anderson@linux.dev


Signed-off-by: Mark Brown <broonie@kernel.org>