i40e/base: remove useless code for pre-boot

The code wrapped in '#ifdef PREBOOT_SUPPORT' was added for
queue context initialization specifically for A0 silicon.
As A0 silicon has gone for a long time, the code should be
removed at all. In addition, the checks of 'QV_RELEASE'
and 'PREBOOT_SUPPORT' are also not needed anymore and can
be removed.

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
Reviewed-by: Chen Jing <jing.d.chen@intel.com>
Tested-by: HuilongX Xu <huilongx.xu@intel.com>