Staging: hv: blkvsc: Get rid of blkvsc_drv.c as this code is not used

Now that blkvsc driver is no longer needed, remove blkvsc_drv.c
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>