defconfig: Enable SPMI debugfs writes for qcs405

Enable SPMI writes in the qcs405 perf-defconfig as
that is the default build config.

Change-Id: If13a2ebe3e0d993370f5d442addee2830d5b671c
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>