drivers: qcom: cmd-db: Export cmd_db_get_aux related APIs

cmd_db_get_aux_data() and cmd_db_get_aux_data_len()
APIs used by the QCOM_KGSL driver. These APIs needs to
be exported to fix compilation errors seen in QCOM_KGSL
loadable module.

Change-Id: I8a6d7b4ed629f7b536adb92be48a71946daff46b
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>