EHCI: HSIC: Halt controller before driving suspend on to the bus

There can be SOFs underway after suspending the port
(setting susp bit) which leads to phy lockup or unexpected
device disconnections. Halt the controller before setting
port suspend bit to avoid such issues.

CRs-Fixed: 363920, 356212
Change-Id: I9ab3fe0556e845621d9314b66d2af955251284fb
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>