iwlwifi: alloc memory dynamically also for DVM

For old firmwares the memory wasn't allocated, resulting in panic.
Make it dynamically allocated as well. Allow any order of functions
call.

Fixes: eef187a7 ("iwlwifi: enlarge number of ucode sections")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Tested-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>