habanalabs: replace GFP_ATOMIC with GFP_KERNEL

As there are incorrect assumptions in which some of the
initialization and data path flows cannot sleep, most allocations
are being done using GFP_ATOMIC.
We modify the code to use GFP_ATOMIC only when realy needed, as
sleepable flow should use GFP_KERNEL.
In addition add a fallback to allocate memory using GFP_KERNEL,
once ATOMIC allocation fails.

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