kirby: Add delay before enabling 3.3V rail

A delay between enabling PMIC_PWRON and 3.3V rail is needed so as to
prevent leakage.

BUG=chrome-os-partner:22101
TEST=Power cycle the AP.
BRANCH=None

Change-Id: I2dd1c7ebc71565fc64dacaeb5caa46b2d3801d50
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/167582
1 file changed