Staging: hv: storvsc: Include storvsc.c in storvsc_drv.c

As part of further cleanup of our storage drivers, include the content
of storvsc.c into storvsc_drv.c and delete storvsc.c and do the necessary
adjustments.

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