bloblist: kconfig for mandatory incoming standard passage

bloblist: kconfig for mandatory incoming standard passage

In previous commit, incoming standard passage is used by default
when initializing the bloblist, so explicitly BLOBLIST_PASSAGE is
no more needed.
Rename it as BLOBLIST_PASSAGE_MANDATORY to determine the behaviors
when an incoming transfer list does not exist or is invalid.
When it is selected, incoming standard passage is mandatory and
U-Boot will report an error when a valid incoming transfer list is
missing.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>