Moved fw readiness check to a new routine bnxt_check_fw_ready().
During error recovery, driver needs to wait for fw readiness.
For that, it uses bnxt_hwrm_ver_get() function now and that
function does parsing of the VER_GET response as well.
Added a new lightweight function bnxt_hwrm_poll_ver_get() for polling
the firmware readiness which issues VER_GET and checks for success
without processing the command response.