defconfig: qcs405: Enable Power driver for BT

Enable config flags for BT power driver for QCS405. This driver sets
the voltage on regulators as per the DTS entries which helps
in powering up BT Chip (WCN3990).

Change-Id: I542beda0dd6a925c35c0256db3011d70bc1df9ad
Signed-off-by: Hemant Gupta <hemantg@codeaurora.org>
Signed-off-by: Himta Ram <hram@codeaurora.org>