cleanup: apply const to read-only iterators
cleanup: apply const to read-only iterators

Apply const to read-only iterators.

Change-Id: Ib58f98596cb9f185d3b16a0b1fbd895dd37d3fd6
Signed-off-by: Patrick Venture <36c53fa43f47f3fd67cb2fc38031827244d18a1f@google.com>

openbmc/phosphor-ipmi-blobs