net/mlx5: Add nic_cap_reg and vhca_icm_ctrl registers

Add nic_cap_reg and vhca_icm_ctrl registers interfaces for exposing ICM
consumption.

Signed-off-by: Akiva Goldberger <agoldberger@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250109204231.1809851-5-tariqt@nvidia.com


Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>