power: supply: qcom: Add 40ms delay before updating 5V VBUS allowance

When charging with some fixed voltage USBPD adapters and when VBUS voltage
is moving from 9V to 5V, usbin-ov interrupt is triggered because of the
VBUS voltage is not settled before updating 5V VBUS allowance. To avoid
this, adding 40ms delay before updating 5V VBUS allowance.

Change-Id: I1a439210e7ceb46bf59f900f3c72e71715c590d3
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>