qed: Add driver API for flashing the config attributes.

The patch adds driver interface for reading the config attributes from user
provided buffer, and updates these values on nvm config flash partition.

This is basically an expansion of our existing ethtool -f implementation.
The management FW has exposed an additional method of configuring some of
the nvram options, and this makes use of that. This implementation will
come into use when newer FW files which contain configuration directives
employing this API will be provided to ethtool -f.

Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>