vboot: introduce vbnv_init()

Add vbnv_init() which is responsible for doing any vbnv initialization
and reading the vbnv contents. Having this function allows for
putting vbnv backing store specific support in the main vboot logic
path.

BUG=b:63054105

Change-Id: Id8f0344e5de5338417ae2e353ae473d6909c860a
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/21550
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
3 files changed