ena-com: add NUMA allocations macros

Add implementation for the ENA_MEM_ALLOC_NODE and
ENA_MEM_ALLOC_COHERENT_NODE_* macros. Also the signature of
ena_dma_alloc() function was updated, for which the implementation
will be updated in ENA driver's patch.

Submitted by: Artur Rojek <ar@semihalf.com>
Submitted by: Dawid Gorecki <dgr@semihalf.com>
Submitted by: Michal Krawczyk <mk@semihalf.com>
Obtained from: Semihalf
Sponsored by: Amazon, Inc.