habanalabs/gaudi: always use single-msi mode

The device can get into deadlock in case it use indirect mode for MSI
interrupts (multi-msi) and have hard-reset during interrupt storm.

To prevent that, always use direct mode which means single-msi mode.

The F/W will prevent the host from writing to the indirect MSI
registers to prevent any malicious user from causing this scenario.

Signed-off-by: Oded Gabbay <ogabbay@kernel.org>