hw/net/can/xlnx-versal-canfd: Fix interrupt level

hw/net/can/xlnx-versal-canfd: Fix interrupt level

The interrupt level should be 0 or 1. The existing code was using the
interrupt flags to determine the level. In the only machine currently
supported (xlnx-versal-virt), the GICv3 was masking off all bits except
bit 0 when applying it, resulting in the IRQ never being delivered.

Signed-off-by: Doug Brown <doug@schmorgal.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Reviewed-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Message-id: 20240827034927.66659-2-doug@schmorgal.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>