defconfig: qcs405: Enable gpio key driver for qcs405

For input event handling gpio key driver is required,
enabling same for qcs405 platform.

Change-Id: I8243a0521721b4dd5bc6430546d9be5d73319a69
Signed-off-by: Avaneesh Kumar Dwivedi <akdwived@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>