usb: host: tegra: fix usb-device reset in LP0 exit

usb: host: tegra: fix usb-device reset in LP0 exit

While resuming from LP0, ehci getting reset that causes
ip address lost if usb-ethernet dongle is used for
network connection, this is happend because usb-ehci resume
functionality called twice and therefore USB_PORTSC_CCS bit
in register USB_PORTSC get changed, which causes reset command
sent to the utmi.

To maintain uniformity, changes also done in tegra_ehci_suspend.

In the tegra_ehci_probe, unnecessary tried to resume ehci. So,
removing resume functionality while probing ehci.

Bug 1355760

Change-Id: I6b170131704b36e722ed2b8ec2abb770770fd859
Signed-off-by: Jeetesh Burman <jburman@nvidia.com>