usb: xhci-msm-hsic: Handle periph_on signal for hsic system clk

Due to HW connectivity bug driver needs to force periph_on signal
on to prevent hsic core memory to go to retention mode when hsic
is active. Hence enable force-on mode for periph_on signal when
hsic is active and disable it upon entering low power mode.

Also, disable hsic system clk as the last clock upon hsic suspend
and enable hsic clocks in reverse order upon resume.

CRs-Fixed: 581297
Change-Id: I47c38c9e8654505ffebc8605b5198de6589da164
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>