net: airoha: Add the capability to allocate hfwd descriptors in SRAM

net: airoha: Add the capability to allocate hfwd descriptors in SRAM

In order to improve packet processing and packet forwarding
performances, EN7581 SoC supports consuming SRAM instead of DRAM for
hw forwarding descriptors queue.
For downlink hw accelerated traffic request to consume SRAM memory
for hw forwarding descriptors queue.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250521-airopha-desc-sram-v3-4-a6e9b085b4f0@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>