Staging: hv: storvsc: Add the contents of hyperv_storage.h to storvsc_drv.c

As part of further cleanup of storvsc, add the contents of hyperv_storage.h
to storvsc_drv.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>