usb: phy: hsusb: Correct sequence of putting hsusb phy into retention

On few platform there is different programming sequence is being
suggested to put HSUSB phy into retention. Also it is required to use
different set of registers for it. This change implements the same.

CRs-Fixed: 625668
Change-Id: I0a78737f93e0543f30b0278bb3869fb21f3e0b7e
Signed-off-by: Mayank Rana <mrana@codeaurora.org>