i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request

i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request

Bus cleanup path in DMA mode may trigger a RING_OP_STAT interrupt when
the ring is being stopped. Depending on timing between ring stop request
completion, interrupt handler removal and code execution this may lead
to a NULL pointer dereference in hci_dma_irq_handler() if it gets to run
after the io_data pointer is set to NULL in hci_dma_cleanup().

Prevent this my masking the ring interrupts before ring stop request.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20240920144432.62370-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>