Drivers: hv: vmbus: Remove x86-isms from arch independent drivers

hv_is_hypercall_page_setup() is used to check if Hyper-V is
initialized, but a 'hypercall page' is an x86 implementation detail
that isn't necessarily present on other architectures. Rename to the
architecture independent hv_is_hyperv_initialized() and add check
that x86_hyper is pointing to Hyper-V.  Use this function instead of
direct references to x86-specific data structures in vmbus_drv.c,
and remove now redundant call in hv_init(). Also remove 'x86' from
the string name passed to cpuhp_setup_state().

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hv.c

@@ -49,9 +49,6 @@ struct hv_context hv_context = {
  */
 int hv_init(void)
 {
-	if (!hv_is_hypercall_page_setup())
-		return -ENOTSUPP;
-
 	hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
 	if (!hv_context.cpu_context)
 		return -ENOMEM;