devlink: Add macro for "fw.mgmt.api" to info_get cb.

Add definition and documentation for the new generic info
"fw.mgmt.api". This macro specifies the version of the software
interfaces between driver and firmware.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Vasundhara Volam

Documentation/networking/devlink/devlink-info.rst

@@ -157,6 +157,12 @@ Control unit firmware version. This firmware is responsible for house
 keeping tasks, PHY control etc. but not the packet-by-packet data path
 operation.
 
+fw.mgmt.api
+-----------
+
+Firmware interface specification version of the software interfaces between
+driver and firmware.
+
 fw.app
 ------
 

include/net/devlink.h

@@ -481,6 +481,8 @@ enum devlink_param_generic_id {
 #define DEVLINK_INFO_VERSION_GENERIC_FW		"fw"
 /* Control processor FW version */
 #define DEVLINK_INFO_VERSION_GENERIC_FW_MGMT	"fw.mgmt"
+/* FW interface specification version */
+#define DEVLINK_INFO_VERSION_GENERIC_FW_MGMT_API	"fw.mgmt.api"
 /* Data path microcode controlling high-speed packet processing */
 #define DEVLINK_INFO_VERSION_GENERIC_FW_APP	"fw.app"
 /* UNDI software version */