wimax/i2400m: drop support for deprecated major fw interface, add for new minor

Firmware interface version 8.x.x has long been deprecated and is no
longer supported (nor available, as it is a preproduction firmware),
so it can be safely dropped.

Add support for firmware interface v9.2.x (current is 9.1.x). Firmware
version 9.2.x is backwards compatible with 9.1.x; new features are
enabled if switches are pressed to turn them on. Forthcoming commits
to the driver will start pressing those switches when the firmware
interface supports it.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>