The Mbox interface requires structure 'qmp_pkt' which is defined
only when kernel config CONFIG_MSM_QMP is enabled, so add
conditional compilation for these interfaces (controlled by
config CONFIG_MSM_QMP).
While at the same time, qmp_get/qmp_put/qmp_send are controlled
by kernel config CONFIG_QCOM_AOSS_QMP, but they are defined
even when CONFIG_QCOM_AOSS_QMP is disabled, so conditional
compilation is not needed.

Change-Id: I0f793ae3661fb901edc857af0b1d4191d7c113f8
CRs-Fixed: 3712102