mlxsw: reg: Add Management Capabilities Mask Register

MCAM register reports the device supported management features. Querying
this register exposes if features are supported with the current
firmware version in the current ASIC. Then, the driver can separate
between different implementations dynamically.

MCAM register supports querying whether the MCIA register supports 128
bytes payloads or only 48 bytes. Add support for the register as
preparation for allowing larger MCIA transactions.

Note that the access to the bits in the field 'mng_feature_cap_mask' is
not same to other mask fields in other registers. In most of the cases
bit #0 is the first one in the last dword, in MCAM register, bits #0-#31
are in the first dword and so on. Declare the mask field using bits
arrays per dword to simplify the access.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/1427a3f57ba93db1c5dd4f982bfb31dd5c82356e.1690281940.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>