soc: qcom: pdr: Make QMI message rules const

Commit ff6d3658 ("soc: qcom: qmi: use const for struct
qmi_elem_info") allows QMI message encoding/decoding rules to be
const, so do that for QCOM PDR.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220914234705.28405-5-quic_jjohnson@quicinc.com