libc2dcolorconvert: use c2dMapAddr() and c2dUnMapAddr

These apis are the preferred way to map ION memory into C2D,
instead of direct kgsl calls.

Change-Id: I74de60c1a407aa507e3f47edc5074b4df3928da3
Merge branch 'jb_2.6_1' of git://codeaurora.org/platform/hardware/qcom/media into cm-10.2