mlxsw: cmd: Edit the comment of 'max_lag' field in CONFIG_PROFILE

Starting from Spectrum-4, the maximum number of LAG IDs can be configured
by software via CONFIG_PROFILE command during driver initialization.

Edit the comment of 'max_lag' field to mention that this field is reserved
in Spectrum-1/2/3 and describe firmware behavior.
Signed-off-by: NAmit Cohen <amcohen@nvidia.com>
Reviewed-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlxsw/cmd.h

@@ -703,6 +703,9 @@ MLXSW_ITEM32(cmd_mbox, config_profile, max_vepa_channels, 0x10, 0, 8);
 
 /* cmd_mbox_config_profile_max_lag
  * Maximum number of LAG IDs requested.
+ * Reserved when Spectrum-1/2/3, supported from Spectrum-4 and above.
+ * For Spectrum-4, firmware sets 128 for values between 1-128 and 256 for values
+ * between 129-256.
  */
 MLXSW_ITEM32(cmd_mbox, config_profile, max_lag, 0x14, 0, 16);