usb: hsic: Add support to reinitialize HSIC without reboot

There is a requirement to support reinitialization of HSIC connection
without rebooting. Add changes to support this using sysfs node.

/sys/devices/platform/msm_hsic_peripheral/hsic_init is the node used
to do this initialization. On writing 0 to it HSIC is put into LPM, on
writing 1 after bringing HSIC out of LPM, initlization like boot time
is done.

Following are the steps to perform this reinitialization
Before rebooting the AP
echo 0 >  /sys/devices/platform/msm_hsic_peripheral/hsic_init

After rebooting the AP
echo 1 >  /sys/devices/platform/msm_hsic_peripheral/hsic_init

Change-Id: I12efa47ad82adec2cf6a35321d90c0958de5ce50
Signed-off-by: Tarun Gupta <tarung@codeaurora.org>