[PATCH] libertas: pass boot2 version to firmware

Boot2 version used to be hardcoded in the uploaded firmware,
this patch preserves the boot2 version before uploading firmware
and sends it to the firmware again on resume.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>