SM5803: Ramp Vbus output voltage
SM5803: Ramp Vbus output voltage

If the initial Vbus voltage for a peripheral is set to 5.0 V, the signal
may overshoot beyond spec.  Vbus should be set to 4.8 V to begin with,
and then ramped up to 5.0 V after 4 ms.

BRANCH=None
BUG=b:153899150
TEST=on waddledee, verify that Vbus doesn't overshoot past allowed
range

Signed-off-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>
Change-Id: Ie17e2e3a3e67c0773f7e3f8f33d80b97f3c16adc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2405492
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec