MLK-10179-1 usb: chipidea: add a flag for turn on vbus early for host

MLK-10179-1 usb: chipidea: add a flag for turn on vbus early for host

Some PHY of imx usb need power supply from vbus to make it work, if there
is no vbus, USB PHY will not in correct state when the controller starts to
work, for host, this requires vbus should be turned on before setting port
power(PP) of ehci, to work with this kind of USB PHY design, this patch adds
a flag CI_HDRC_IMX_VBUS_EARLY_ON, can be checked by host driver to turn on
vbus while start host.

Signed-off-by: Li Jun <jun.li@freescale.com>
(cherry picked from commit 1d4c054323817b49897fd7a59bc57b4d36f09491)