edgetpu: remove dependency on iommu_group_id

A dev_dbg line was using iommu_grou_id, but this function is not part of
KMI. Removing the line to avoid a build failure when building against
Pixel kernels with -DDYNAMIC_DEBUG_MODULE enabled.

Bug: 186701019
Signed-off-by: Thierry Strudel <tstrudel@google.com>
Change-Id: I6e1cdb710e62ce88057c8457de486f06eb8edb06
Signed-off-by: Erick Reyes <erickreyes@google.com>