Staging: hv: Move the definition of the function stor_vsc_on_host_reset()

stor_vsc_on_host_reset() function is only used in storvsc_drv.c.
Move this function from storvsc.c to storvsc_drv.c

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>