habanalabs: give FW a grace time for configuring iATU

iATU (internal Address Translation Unit of the PCI controller)
configuration is being done by FW right after driver enables
the PCI device. Hence, driver must add a minor sleep afterwards
in order to make sure FW finishes configuring iATU regions.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>