drm/msm/dp: update log for simulated AUX transfers

Update log for simulated aux transfers to make it Debug
level. This change will prevent unnecessary logs for AUX
transfers that are not yet supported in the simulation.
For example, DPCD access to DPRX_FEATURE_ENUMERATION_LIST
at address 2210h is not supported in simulation since this
is not critical to DP functionality.

CRs-Fixed: 2332446
Change-Id: I7a758a5b2c7305a9f4cb1eb386ab59477f505ce3
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>