Add support for 1G SFP data rate on WHLE-LS1046A. This release adds additional firmware build for WHLE-LS1046A which enabled 1Gbit/sec speed on both SFP+ ports. It can be used in deployments where 1000Base-X support is needed. Additionally, each SFP/SFP+ port can be forced into `fixed-link` mode in the device tree passed to the kernel. `fixed-link` mode removes the association between the Ethernet MAC and SFP transceiver, essentially forcing the link to be up all the time and ignoring link state information coming from the transceiver. It can be enabled using the following commands: setenv sfp1_fixed_link y # for SFP1 setenv sfp2_fixed_link y # for SFP2