defconfig: msm: Enable DEBUG_PREEMPT config on trinket

Enable DEBUG_PREEMPT kernel config to support debugging
preemptible kernel. This config helps in identifying
executing context on preemptible kernels.

Change-Id: Iacdcfbadddd0d400415d3e45d42fcfa78a7fa176
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>