Synchronize link speed with boot driver

Link speed settings set by the boot driver are reported by the hw.
Driver will attempt to read them, and if set, will respect their
values.
The driver can override the settings with its own if instructed by
user space (via bsg), with the new values being picked up by the
boot driver.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>