defconfig: msm8610: Enable Diag char driver

Diag char driver is not enabled for msm8610 so
diag not initializes and not opening USB legacy channel
and hence adb is not working. This patch enables diag
character driver.

Change-Id: Ic907081f6134157bab08dc2ba00bc57da3171d1a
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>