Currently all usage of struct qmi_elem_info, which is used to define
the QMI message encoding/decoding rules, does not use const. This
prevents clients from registering const arrays. Since these arrays are
always pre-defined, they should be const, so add the const qualifier
to all places in the QMI interface where struct qmi_elem_info is used.

Once this patch is in place, clients can independently update their
pre-defined arrays to be const, as demonstrated in the QMI sample
code.
Signed-off-by: NJeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: NBjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220822153435.7856-1-quic_jjohnson@quicinc.com